synthetic vs. conventional

[Saved]

First let me say that I have been in the oilfield business for years and have experience with synthetics as well as seen the engineering claims. Most are a bunch of poppycock just to sell the product and once the mind is convinced that synthetic is the cure all it is just about impossible to show a person other wise. That is not to say that synthetic oil is no good. It is if used where it is really needed. However Synthetic is mostly nothing but a hype when it comes to most conventional engines. Unless the engine oil is running above normal temps synthetic is a total waste of money. Now for those who swear by it in conventional engines by all means keep buying it, as it is your money to waste, but I challenge you to take two vehicles and treat them exactly the same and you will see that neither will do better then the other.
While there are claims that synthetic will get you extra miles there is not single study to prove it. No one has ever taken two identical vehicles and put them through exact normal driving one with synthetic and one with conventional oil and proven that synthetic makes the engine last longer. Keep in mind we are talking about the standard engines, not a NASCAR race engine or a dragster. Even the weekend hot rodder does not need synthetic as synthetic will only benefit the engine IF the engine oil is running too hot.
I have a ford truck that I have only used conventional oil in and I have over 400,000 miles on it and it does not use a drop between oil changes. I once had a motor cycle and used synthetic in it. I got about 75,000 mile on the engine. I put a new engine (not rebuilt) in it and went to conventional oil and went just as far on the second engine.
Also if you do the math synthetic costs more without any real benefit except that you can go longer between oil changes. So for 50% extra you can be hyped up and think you are doing something by using synthetic while the manufacture laughs all the way to the bank, but I suggest that you use conventional oil and change it as recommended. You will get the same benefits and have extra money in the bank.
One more thing. Some will try and tell you that synthetic is slipperier then conventional. That is more hype. The industry has standards and they are listed on the oil we buy as to how slippery it is. SM is the highest you can buy and conventional oils come in that grade. Here is a chart Motor Oil Grades and Service Ratings
Here is another article that gives some information. Car Bibles : The Engine Oil Bible
So if the manufacture calls for synthetic use it. If it is not exactly specified (required) then use the conventional and save a ton of money. You will get the same life out of your engine with conventional oil. Believe me IF synthetic oil was as good as some claim every manufacturer would require it for warranty purposes, but very few do. So unless you are building an extremely high performance off road vehicle use conventional oil.

 

[Mr. Leary]

I disagree. Its not the oil that breaks down during use, rather the additives to the oil. Synthetic oil is a better medium for these lubricating additives, so it lasts longer. Dinosaur oil will hold them just as well for a little while, but failure to stay on top of the interval can quickly lead to engine damage. Spinning up for too long or excess heat buildup like we see in heavy towing or off road use makes the dino oil medium less then ideal.

Now which type of oil you are using matters much less then the fact that you stay on top of regular maintainance. The fact that you put 400k on your Ford was no coincidence. I'll bet you rarely if ever missed an oil change interval. Failure to perform regular and preventitive maintainance is the single biggest cause of mechanical failure, period.

I change oil every 5k in all my vehicles. I would rather spend a little more and sleep better knowing that my old trucks are better lubricated now then they ever have been! :reddance:

 

[Nunyabiz]

You are not "saving money" using conventional oil, in fact just the opposite.

Also in several engines like my wifes Lexus for example I don't care how often you change conventional oil you can get sludge because of how hot that engine gets.
When you shut that engine off and the oil runs back down a thin film of oil remains on top and if it is convention oil it sits there and literally cooks and starts clogging up those tiny oil channels.
Synthetic oil has a MUCH higher flash point thus will not cook in that engine.

Conventional oil after just a couple hundred miles has broken down quite a bit because of it while the synthetic is basically untouched.

Since I only drive usually less than 8000 miles a year I change my oil once a year using synthetic.
If using conventional I would have to change oil at least twice if not 3X during that year.

You don't waste money using synthetic at all.

As far the effectiveness of synthetic oil what sold me back in 1977 was I used to own a Baja Bug, really nice engine in it a 2180cc nicely built, VW racing heads putting out about 220hp.
Only problem I had with it was it would get hot and lose considerable power especially if I took it to the desert and romped on it.
I tried everything, put in a deep sump, all stainless lines and a oil cooler on the roof under a scoop which added A LOT of extra oil and cooling on and oil cooled engine but to no avail. Used every kind of conventional oil there was. Still would over heat and lose power.

A friend of mine tried amsoil in his bug and liked it, at the time all they had I think was what they called 20/50 racing oil.
I put that in my Bug and Viola, never over heated again, never lost power no matter how hard I pushed it. SOLD!
So I KNOW that synthetic is superior oil, I have seen the results of it too many times.

Also my wifes Lexus when we first got it had a fresh oil change of conventional oil in it from Carmax so we let it go about 1000 miles prior to changing it because they just put it in the day we bought it.
We went through about 3 tanks of gas and one tank was a long trip.
we got just over 26 mpg. That was with whatever 5W30 dino they put in.
Changed to 0W30 Amsoil and have gotten up to 31mpg on a long trip straight hwy miles.
Also this engine is one of the worst for sludge because the top end gets so hot.

We have had it for 7 years now and I had my mechanic take a look at it last year and it was clean as a whistle inside, zero sludge.
My Jeep I just sold with its straight 6 was same way, mechanic said it looked new inside it was so clean and it was a 94' YJ with 150xxx miles.

Synthetic makes a huge difference in some engines.

Also I might add if you have an older vehicle that runs flat tappets etc, those engines were made to use very high ZDDP oil which all oils used to be many years ago, high levels of Zinc & phosphorus was the norm.
You are basically killing your classic car engine if you run standard conventional oil in it today.
Most synthetics have higher ZDDP.

Personally I have yet to own a car/truck that has not benefited from Synthetic oil and that is everything from VWs both raced out and dead stock, diesels, 4/6/8 cylinders Hondas, VWs, Fords, Dodge, Lexus, Jeep and now that I think about it even my motorcycle and outboard engines on my boat which were 2 & 3 cylinder.

I will trust my 34 years of using synthetic exclusively in every engine I have owned over whatever I read any day.
Oh hell I even run it in my pressure washer in an old Briggs and Stratton forgot about that, so that is the whole gambit 1,2,3,4,5,6,8 cylinders.

In general in most applications running synthetic will probably "save" you money, has for me for 34 years.

 

[rickashay]

wow, there is a lot of info being tossed around here. This is an age old debate.

From my personal experience:

While I attended post secondary for Petroleum Engineering we had to do several Chem. labs on the lubricating properties of various oils at various temperatures. Most oils we tested were conventional and we also tested Castrol Syntec and Mobile 1 at 5W30 weights for all of the oils. Mobile 1 literally destroyed ALL of the other oils in this experiment. (I did this approx. 8 years ago, sorry I wish I could remember all of the exact details....)

I switched to Mobile 1 on my last Toyota. It had 145 000 miles on the clock when I switched. I had a few leaks "appear" after the switch to synthetic which cost quite a bit to fix. (Synthetic doesnt cause leaks, but I DO believe that is lubricated and cleans better therefore as said above, the synthetic just revealed an existing issue. I had no increase in fuel economy with the switch.

In the Honda Accord I owned prior to my last Toyota: Switched to synthetic at 100 000 miles. No leaks were revealed and my gas mileage increased 10% after the switch, which still amazes me.... must have been because of the better lubricating properties.

I have also heard that the technology going into conventional oils is getting progressively better and that the gap in oil performance between conventional and synthetic is constantly decreasing. However, I have no proof to back that claim up.

 

[Orange Skullz]

First let me say that I have been in the oilfield business for years and have experience with synthetics as well as seen the engineering claims. Most are a bunch of poppycock just to sell the product and once the mind is convinced that synthetic is the cure all it is just about impossible to show a person other wise. That is not to say that synthetic oil is no good. It is if used where it is really needed. However Synthetic is mostly nothing but a hype when it comes to most conventional engines. Unless the engine oil is running above normal temps synthetic is a total waste of money. Now for those who swear by it in conventional engines by all means keep buying it, as it is your money to waste, but I challenge you to take two vehicles and treat them exactly the same and you will see that neither will do better then the other.
While there are claims that synthetic will get you extra miles there is not single study to prove it. No one has ever taken two identical vehicles and put them through exact normal driving one with synthetic and one with conventional oil and proven that synthetic makes the engine last longer. Keep in mind we are talking about the standard engines, not a NASCAR race engine or a dragster. Even the weekend hot rodder does not need synthetic as synthetic will only benefit the engine IF the engine oil is running too hot.
I have a ford truck that I have only used conventional oil in and I have over 400,000 miles on it and it does not use a drop between oil changes. I once had a motor cycle and used synthetic in it. I got about 75,000 mile on the engine. I put a new engine (not rebuilt) in it and went to conventional oil and went just as far on the second engine.
Also if you do the math synthetic costs more without any real benefit except that you can go longer between oil changes. So for 50% extra you can be hyped up and think you are doing something by using synthetic while the manufacture laughs all the way to the bank, but I suggest that you use conventional oil and change it as recommended. You will get the same benefits and have extra money in the bank.
One more thing. Some will try and tell you that synthetic is slipperier then conventional. That is more hype. The industry has standards and they are listed on the oil we buy as to how slippery it is. SM is the highest you can buy and conventional oils come in that grade. Here is a chart Motor Oil Grades and Service Ratings
Here is another article that gives some information. Car Bibles : The Engine Oil Bible
So if the manufacture calls for synthetic use it. If it is not exactly specified (required) then use the conventional and save a ton of money. You will get the same life out of your engine with conventional oil. Believe me IF synthetic oil was as good as some claim every manufacturer would require it for warranty purposes, but very few do. So unless you are building an extremely high performance off road vehicle use conventional oil.

I like your statement about having a FORD with 400,000+ and not using a drop.......B.S.!! plain and simple.

I've owned a few vehicles from Ford ranging from brand spanking new to cars with over 150,000 miles when I bought them.

EVERY.......yes EVERY one has used oil. Fords will use a quart of oil every 5000 miles. And that you can take to the bank.

Synthetics will also reduce oil tempature by 20+ degrees. And can also provide an extra mile or 2 to a gallon of gas due to reduced friction.

I run Synthetic in my motorcycle and it reduced oil temp by 25 - 30 degrees on an Air-Cooled V-Twin.

And were talking about a motor that will cost you $8 - $9g to replace (a 124ci S&S show polished V-Twin).

Your claims that Dino oil matches up to Syn oil is NUTS!!

 

[IanB]

Thats diesel oil dude.

Alot of the turbo Subaru guys swear by Rotella, branded for diesel use or not. It deals with the rigors of a turbocharged engine quite nicely, and won't hurt a gas engine by using it.

 

[Singtoe]

I think synthetics have their place. Not in my 4runner though.

I have an Audi A6 Bi-turbo and it requires synthetic. If you ran regular oil in it, the turbo journals and drain tubes would cake up so quickly, the turbos would die a violent and painful death.

I am doing the schedule A in Mercedes CLK 500 and Mercedes recommended service interval is 13,000 miles. It comes from the factory with Mobil1 0-40w. This engine has sludge in the valve cover area. So don't tell me an engine running synthetics won't sludge because it will.

My 4runner has been using castrol gtx for the past 100k miles and there is not one bit of sludge in the valve cover area.

The bottom line is - If you are going to change your oil every 3 to 4k miles, then stick with Dino Oil. If you are going to change it every 10k miles, then use Synthetic oils.


Definitely don't run Synthetic oils in the 4runner's diffs. That is a sure way to start and cause problems. It is too thin and doesn't offer the tackiness that conventional oils have. Gears and bearing run dry after sitting for a while and that leads to other issues.

I recommend using Lucas oils in the diffs.

 

[TheDurk]

Alot of the turbo Subaru guys swear by Rotella, branded for diesel use or not. It deals with the rigors of a turbocharged engine quite nicely, and won't hurt a gas engine by using it.

Tractor guys use it in their gas tractors--it has the ZDDP they took out of all the gas dino oils. I use syn in my cars(6-7K OCI), but the tractor gets Rotella 15W-40 every six months.

 

[Saved]

I like your statement about having a FORD with 400,000+ and not using a drop.......B.S.!! plain and simple.

I've owned a few vehicles from Ford ranging from brand spanking new to cars with over 150,000 miles when I bought them.

EVERY.......yes EVERY one has used oil. Fords will use a quart of oil every 5000 miles. And that you can take to the bank.

Synthetics will also reduce oil tempature by 20+ degrees. And can also provide an extra mile or 2 to a gallon of gas due to reduced friction.

I run Synthetic in my motorcycle and it reduced oil temp by 25 - 30 degrees on an Air-Cooled V-Twin.

And were talking about a motor that will cost you $8 - $9g to replace (a 124ci S&S show polished V-Twin).

Your claims that Dino oil matches up to Syn oil is NUTS!!

I have seen guys like you. All mouth and no back bone. Here the deal. I will put up 10,000 dollars and you do the same both in one account. We will sign an agreement with witness'. We will change the oil on this truck together and then take a 5000 mile trip. We will then drain the oil. If it is 1 quart low after 5000 miles you get both mine and your 10,000. If not I get both. Now put up or shut up. By the way I am willing to bet you cannot reproduce the same results you boasted about on your other stats either but lets take care of this other first. Let's see who is slinging BS!

 

[Nunyabiz]

There is zero difference in viscosity between conventional oil and gear lube Vs Synthetic oil & gear lube.
I cant understand why people believe the synthetic is "thin".

5W30 is 5W30 period whether it is Dino or Synthetic same with gear lube 75W90 is 75W90. The advantage of synthetic is it adheres to the metal much better the superior additives form an iron-sulfide barrier that stick to the gears no matter how long they sit.

If anything it keeps its viscosity longer at temp than dino oil does and like all multi viscosity oils & lubes the hotter it gets the higher the viscosity becomes.

There is zero difference between dino gear lube Vs synthetic other than the synthetic last longer and protects better.

I wouldn't run anything but synthetic gear lube, ran it in my Jeep for 10 years without a single problem, ran it in my Ford F250 4X4 diesel without a single problem and I am running it in my 4Runner and no doubt will be without a single problem.

The problem with a Mercedes sludging while using synthetic is because of the 13,000 mile interval while using Mobil 1.
With Mobil 1 I would not exceed 6000 to 7000 miles tops.
Synthetics could also sludge if the head gasket is leaking coolant into the oil.

But you use a quality synthetic and "decent" intervals and you don't have any other problems like coolant leaking into oil then you will never get sludge. Under normal conditions synthetics have more life left in them at 8000 miles than conventional oils do at 2000, plus always much higher flash point so if an engine sludges with synthetic oil then you got either serious problem with your engine or you let the oil go WAY longer than it should and let it break down to conventional oil levels of protection.

 

[Singtoe]

There is zero difference in viscosity between conventional oil and gear lube Vs Synthetic oil & gear lube.
I cant understand why people believe the synthetic is "thin".

5W30 is 5W30 period whether it is Dino or Synthetic same with gear lube 75W90 is 75W90. The advantage of synthetic is it adheres to the metal much better the superior additives form an iron-sulfide barrier that stick to the gears no matter how long they sit.

If anything it keeps its viscosity longer at temp than dino oil does and like all multi viscosity oils & lubes the hotter it gets the higher the viscosity becomes.

There is zero difference between dino gear lube Vs synthetic other than the synthetic last longer and protects better.

I wouldn't run anything but synthetic gear lube, ran it in my Jeep for 10 years without a single problem, ran it in my Ford F250 4X4 diesel without a single problem and I am running it in my 4Runner and no doubt will be without a single problem.

The problem with a Mercedes sludging while using synthetic is because of the 13,000 mile interval while using Mobil 1.
With Mobil 1 I would not exceed 6000 to 7000 miles tops.
Synthetics could also sludge if the head gasket is leaking coolant into the oil.

But you use a quality synthetic and "decent" intervals and you don't have any other problems like coolant leaking into oil then you will never get sludge. Under normal conditions synthetics have more life left in them at 8000 miles than conventional oils do at 2000, plus always much higher flash point so if an engine sludges with synthetic oil then you got either serious problem with your engine or you let the oil go WAY longer than it should and let it break down to conventional oil levels of protection.

So your saying that Mercedes is wrong for setting the service interval so high. If they ran conventional oil in it, it would have gunked up past the point of being operation after the 3rd oil change.

Changing synthetic oil at 6000 to 7000 miles is too wasteful.

What benefits are there to synthetics if you are changing that often. I thought longer service life and higher boiling point. Changing at 6000 is like changing dino oil at 2000 miles. Sounds like money wasted.


And Somebody explain to me what flash point is because it really has nothing to do with the performance of oil. I could be wrong but I'd like to know.

 

[Nunyabiz]

So your saying that Mercedes is wrong for setting the service interval so high. If they ran conventional oil in it, it would have gunked up past the point of being operation after the 3rd oil change.

Changing synthetic oil at 6000 to 7000 miles is too wasteful.

What benefits are there to synthetics if you are changing that often. I thought longer service life and higher boiling point. Changing at 6000 is like changing dino oil at 2000 miles. Sounds like money wasted.


And Somebody explain to me what flash point is because it really has nothing to do with the performance of oil. I could be wrong but I'd like to know.

Yep they are.
Manufacturers always use mobil 1 because it is available world wide and get it anywhere but it is not the best Synthetic, RedLine and Amsoil are considerably better oils but you can not get either one at Wallyworld or one some street corner in Belize.

Flash point is the temperature at which an oil gives off vapors that can be ignited with a flame held over the oil. The lower the flash point the greater tendancy for the oil to suffer vaporization loss at high temperatures and to burn off on hot cylinder walls and pistons. The flash point can be an indicator of the quality of the base stock used. The higher the flash point the better.

Flash point on 5W30 Amsoil is 478 degrees, ALL synthetics are above 410 I am pretty sure.
Most conventional oils are between 350-380 I think.

What breaks down motor oil is HEAT, the better oil can handle heat the longer it last and better it protects.
Petroleum oil is comprised of various sized molecules, some tiny some large, the tiny molecules are what burn off first, that leaves a high ash content in the oil which is what creates sludge.
In petroleum based oil this happens almost immediately, they start breaking down very quickly.
Synthetic oil does a much better job of cooling the engine, components within the engine usually run 15-30 degrees cooler than with petroleum.
Synthetic oil molecules are basically created all the same size so what little does burn off what is left is still the same characteristics it does not degrade nearly as fast as petroleum.

That fact is why I was sold on synthetic oil to begin with back in 1977 with my old Baja Bug, engine ran much cooler.

I usually change my Amsoil once a year which is usually around 8000ish miles for me but I wouldn't have a problem taking the Amsoil out to 10,000 or so especially if a few 1000 were highway miles, same with Redline which is another excellent oil.
Mobil 1 not so much, 7000 and its time to go, 13,000 on Mobil is quite a bit past where it should be.
If you want to take a synthetic to 13,000 or more then use Amsoil or Redline and a bypass filter because much past 8000-10,000 miles and you have to worry about the filter as much as the oil, even if your oil is still decent the filter probably wont be.
The Amsoil filters are quite good, so are the K&N oil filters but even though they are supposed to go up to 15,000 miles (Amsoil filter) I don't trust it past 10K.

Because my Diesel truck used so much oil was 9 Qts I think I had to use a bypass filter in it so i could take the oil to at least 8000 miles so I could warrant using the higher cost synthetic, because diesel dirties up oil rather quickly so need a really good filter to keep it clean. If not best to just use the Rotella and change it every 3000.

 

[Singtoe]

Flash point is the temperature at which an oil gives off vapors that can be ignited with a flame held over the oil. The lower the flash point the greater tendancy for the oil to suffer vaporization loss at high temperatures and to burn off on hot cylinder walls and pistons. The flash point can be an indicator of the quality of the base stock used. The higher the flash point the better.

Flash point on 5W30 Amsoil is 478 degrees, ALL synthetics are above 410 I am pretty sure.
Most conventional oils are between 350-380 I think.

So your saying that anybody using conventional oil will have a ticking time bomb with potential explosive vapors.

Highly unlikely.

Yes - regular oil has a flash point of 392 and synthetics are higher at 450 but that has got nothing to do with the internal combustion engine. Oil temperatures seldom get higher then 240 degrees Fahrenheit. Even at the piston walls. I have torn down, many engines and i have never seen burnt oil on the cylinder walls. I have seen carboned up rings but that is a byproduct of combustion. If the Temp hit 392 degrees, catastrophic failure will occur.

They only area where a motor might see those temps are the turbos in blown motors. And only then, when the motor has just been turned off and the oil that is sitting in the turbo housing is absorbing all the residual heat from being run extremely hard. (Thus turbo timers)

So there again, flash point has nothing to do with the usefulness of oil in our engines.

Mind you, I use Synthetics where they are needed (Audi Bi-turbo) but for the 4runner. I plan on keeping it for a long time and I plan on changing the oil every 3k miles.




One other point. You said that synthetics stick to metal parts better. Haven't you been to the parts store and seen the LUCAS stack 3 gear demo box. It had a little crank handle on it. you turn the bottom gear and the top gear got a nice coat of oil on it. Vs the other synthetic oil, which you spin the bottom gear as hard as you can and the top gear doesn't get nearly the same amount of oil. Just an observation I had.

 

[Nunyabiz]

So your saying that anybody using conventional oil will have a ticking time bomb with potential explosive vapors.

Highly unlikely.

Yes - regular oil has a flash point of 392 and synthetics are higher at 450 but that has got nothing to do with the internal combustion engine. Oil temperatures seldom get higher then 240 degrees Fahrenheit. Even at the piston walls. I have torn down, many engines and i have never seen burnt oil on the cylinder walls. I have seen carboned up rings but that is a byproduct of combustion. If the Temp hit 392 degrees, catastrophic failure will occur.

They only area where a motor might see those temps are the turbos in blown motors. And only then, when the motor has just been turned off and the oil that is sitting in the turbo housing is absorbing all the residual heat from being run extremely hard. (Thus turbo timers)

So there again, flash point has nothing to do with the usefulness of oil in our engines.

Mind you, I use Synthetics where they are needed (Audi Bi-turbo) but for the 4runner. I plan on keeping it for a long time and I plan on changing the oil every 3k miles.




One other point. You said that synthetics stick to metal parts better. Haven't you been to the parts store and seen the LUCAS stack 3 gear demo box. It had a little crank handle on it. you turn the bottom gear and the top gear got a nice coat of oil on it. Vs the other synthetic oil, which you spin the bottom gear as hard as you can and the top gear doesn't get nearly the same amount of oil. Just an observation I had.

Don't think you are quite understanding the concept of what flash point means, doesn't mean its going to blow up.
Only about 10% if the gas burned gets used to move the car forward the other 90% gets turned into HEAT.
Gets pretty hot in any kind of engine not just a turbo. Hell even the damn water inside the engine is 200 freaking degrees. But I digress.

But in general a higher flash point means the oil is more stable across all temperature ranges thus does not degrade as quickly. Whether it gets over 350 degree is moot. Look at it this way, if you have a rope with a breaking strength of 480lbs Vs a rope with a breaking strength of 350lbs and you use that rope every day pulling 350lbs up & down for hours a day, what rope do you think is going to last longer? The one that is right at it breaking strength or the one that has another 130 lbs left in reserve?

Lucas is just thick, doesn't particularly adhere to metal better especially at high temps. I could put molasses in that same dohicky and I am sure it would climb right to the top like the Lucas does but i am not going to run it in my engine.

I can see you are pretty set in your opinion and so am I so probably not much point in continuing this.
I would suggest that you run your conventional oil and change it at 3K and I am sure everything will be fine.
I will run my synthetic to 8K and also everything will be fine.

Funny thing is it appears as though you accept that synthetic is is indeed better oil but basically that your 4runner doesn't really deserve it.

Whereas I believe even my pressure washers Briggs & Stratton deserves it.

 

[Singtoe]

But in general a higher flash point means the oil is more stable across all temperature ranges thus does not degrade as quickly. Whether it gets over 350 degree is moot. Look at it this way, if you have a rope with a breaking strength of 480lbs Vs a rope with a breaking strength of 350lbs and you use that rope every day pulling 350lbs up & down for hours a day, what rope do you think is going to last longer? The one that is right at it breaking strength or the one that has another 130 lbs left in reserve?

You and analogies. If I am going to be carrying a load that wasn't going to exceed the breaking strength by 100 pounds then why would i spend money on a more expensive rope.

Lucas is just thick, doesn't particularly adhere to metal better especially at high temps. I could put molasses in that same dohicky and I am sure it would climb right to the top like the Lucas does but i am not going to run it in my engine.

Their 80/90w gear oil is what it is. By definition their 80/90w oil viscosity is rated rated at that and not any more. Come on man - Lucas is thick.

I can see you are pretty set in your opinion and so am I so probably not much point in continuing this.
I would suggest that you run your conventional oil and change it at 3K and I am sure everything will be fine.
I will run my synthetic to 8K and also everything will be fine.

Funny thing is it appears as though you accept that synthetic is is indeed better oil but basically that your 4runner doesn't really deserve it.

24k gold terminals are better then the 4runners standard terminals so why not upgrade and switch all the terminals out? Why not upgrade the spark plug wires to 12mm verses the stock 5mm? Why not switch out the air in your tires with Nitrogen? Because the net gains don't outway the net cost. Same with synthetic oil.

Whereas I believe even my pressure washers Briggs & Stratton deserves it.

I run a high detergent single weight oil in mine and I change it yearly. I want it to run clean and work with the splash system that B&S engines use, i follower their recommended oil guidelines.

synthetic is great but it is over kill in our 4runners, unless you are changing your oil every 10k.

The new Toyota Camary now requires Synthetic (0w-20w) and toyota's recommended service interval is 10,000 miles.

 

[TheDurk]

Whereas I believe even my pressure washers Briggs & Stratton deserves it.

I'm pretty much with you up to here. But unfiltered seasonal homeowner-type single-cylinder engines need frequent changes much more than they need higher performing oil. I have an ancient fleet of B&S and Honda single cyls going up to 50 years old on B&S and twenty-five on Honda and I have never lost a 4-stroke engine with dino oil. I had one 1938 Homelite 2-stroke generator die (no oil to change--obviously). Change it every season and those motors really don't care. Now you're using 10-ton wire cable to lift a shoe box.

If I were a contractor with constant use, I'd go to syn, though.

 

[Nunyabiz]

synthetic is great but it is over kill in our 4runners, unless you are changing your oil every 10k.

The new Toyota Camary now requires Synthetic (0w-20w) and toyota's recommended service interval is 10,000 miles.

No such thing as overkill with lubrication, it is the lifes blood of your engine.

About time Toyota started wising up, I guess a few billion dollars lost from the sludge problems woke them up. Although I think the 10,000 mile interval is a bit of a stretch though especially since 8 outa 10 owners will use Mobil 1.

I save money using synthetic changing it at 8k.
I wouldn't trust petroleum oil of any kind past 3K at the most.
In order to come close to the same protection I get with synthetic changed around 8K (1 Year) I would have to change my petroleum oil 3 times in that same year so I would spend MORE using petroleum and not get the benefits of using synthetic.

 

[Nunyabiz]

I'm pretty much with you up to here. But unfiltered seasonal homeowner-type single-cylinder engines need frequent changes much more than they need higher performing oil. I have an ancient fleet of B&S and Honda single cyls going up to 50 years old on B&S and twenty-five on Honda and I have never lost a 4-stroke engine with dino oil. I had one 1938 Homelite 2-stroke generator die (no oil to change--obviously). Change it every season and those motors really don't care. Now you're using 10-ton wire cable to lift a shoe box.

If I were a contractor with constant use, I'd go to syn, though.

I do both since I only use it very infrequently once or twice a year at the most and it only takes such a small amount of oil it basically gets brand new synthetic (Mobil 1) probably every 5 hours of run time. The cost is nominal.

 

[Nelsonmd]

Aside from all the really long posts here, I usually use synthetic (I don't think I have switch the 4runner over yet, but probably will) just because the change interval is longer. I have a long commute, and put miles on pretty quickly, so I hit 3k miles pretty quick.

Here's another question about conventional vs syn oils. Is there really any problem with switching back from synthetic to conventional? I have always heard that there is.

 

[Nunyabiz]

"You and analogies. If I am going to be carrying a load that wasn't going to exceed the breaking strength by 100 pounds then why would i spend money on a more expensive rope."

Because that rope will only last a month or two instead of a year.

"Their 80/90w gear oil is what it is. By definition their 80/90w oil viscosity is rated rated at that and not any more. Come on man - Lucas is thick."

OK, Lucas is thick.
However if I wanted something really thick in my Diff I would use the 75W110 Amsoil but not sure what this has to do with anything.
I use the 75W90 Severe Gear Amsoil, works great.

"24k gold terminals are better then the 4runners standard terminals so why not upgrade and switch all the terminals out? Why not upgrade the spark plug wires to 12mm verses the stock 5mm? Why not switch out the air in your tires with Nitrogen? Because the net gains don't outway the net cost. Same with synthetic oil."

Well I do get Nitrogen in my tires but its free at Costco.
The gains of using synthetic oil far outweigh the cost, in fact it is cheaper.