In light of recent comments by our resident oil expert/mechanic/SK fanboy, I thought id start a thread for what type of oil people use in their 4runners. Feel free to comment the mileage & weight you use, & if you have leaks due to the oil alone.

Apparently, using synthetic oil will cause leaks in all engines, head gasket issues & engine damage� all because synthetic oil is �super slick� & is �cheap�! the only way to avoid this is to use 10/40 conventional oil... but you will still have "1 drop per week!" Oh & by the way, your water pump will only last 4 years! & you should use T-IV trans fluid in your WS spec�d transmission! No, im not making this up!

Haha love it. 134k 5w30 synthetic. switched at 113k. The previous owner did all oil changes at the dealer, so Im guessing it was their conventional oil. no issues as of yet

I have always used Mobil 1 5w-30, regular at first but now high mileage and extended interval. 2004 V8.

In the 13 years I�ve owned my 4Runner, it has never lost a drop of oil. Every time I change the oil, it�s still full. I have never added any oil between oil changes, and there has never been even one drop on the ground under the engine. I don�t have a skid plate, so it�s not like it�s leaking but I can�t see it.

I�m also on my original water pump. I did get the tranny rebuilt at ~175k mikes, but I had been towing for about 10 years.

My 4Runner has been very reliable, as was a Sienna minivan, a Corolla 4-dr and a Corolla All-Trac wagon I owned many years ago. Non-Toyota, a Volvo 240 wagon was also very reliable. I�ve never owned an unreliable car that I can remember. Nothing American and nothing Italian, French, English, etc. First car ever was a VW bug from the 1970�s, super reliable.

I just use conventional and change it out every 3500-4000 miles--I've never had an issue and as far as the maintenance on this 4R goes I abide by the idea of "if it ain't broke, don't fix it."

Edit: I just rolled over 191K a few weeks ago

I switched to Shell Rotella Gas Truck Synthetic 5w-30 at 209k miles and haven't noticed any leaks as a result of the change. I change at 4k so the blackstone numbers all come more or less the same interval. My passenger side valve cover had a slow leak before the switch, and still does afterward. Stick shows around 1/8" below top line at the change interval.

The best part is the head gasket was leaking slightly before the change to full synthetic :P, which was one of his arguments for using conventional. My last oil analysis on the blend showed 50ppm Potassium and 28ppm Sodium in the oil, although the reservoir hasn't dropped much since I marked it about 8 months ago.

I don't have a problem with anyone running synthetic or conventional. My main thing was why that guy was telling us ours should be leaking oil, when several of us had mentioned we made the change without any issues. Also kept using the term "slippery" to try and describe oil, which was amusing. I do feel partially responsible for the mess, since I was the first to take a jab at scotty in his original thread lol

I use Valvoline High Mileage Maxlife

I lose some oil through leaks/burning, but on 17 year old factory seals with 313k miles, that's more than expected - and the loss is barely any compared to what I think it should be

I have yet to do my first oil change as my truck is new to me and currently has 81K miles. The person who sold it to me used conventional oil, but I plan on using synthetic in the near future, and I'm crossing my fingers. My last truck, Infiniti QX4, started leaking at the main seal when I changed to synthetic. So, I'm hoping this doesn't happen to this truck; I love seeing a dry engine bay;)

So, I'm very curious to see how others respond to this thread.

V8

Swapped to synthetic at 130k miles and haven't noticed a drop at over 160k.

I use Liqui Moly long time high tech 5W-30. Get free lifetime replacements from FCP Euro and truck seems to drive great.

Older cars usually have to use conventional motor oil instead of synthetic motor oil. Switching to synthetic can cause engine leaks or engine damage.

What Are the Risks of Switching to Synthetic Oil in Older Cars? | YourMechanic Advice

Captsolo,

Did you read the article your linked too?

Let me quote � Tips for Using Synthetic Oils in Older Models

When using the term older refers to cars, it means those manufactured before 1990 or so. The risk with these models is that the seals, gaskets, and other components often aren�t as tight as with newer models�

Last I checked 4th gen T4R are 2003 and newer. The seals that we used back then were crappy cork rubber seals that needed the crud to plug up leaks. Modern seal dont fail like that any more.

& there he is with more of his links he found on google! LOL! you should read your own links before posting, did you miss the part that says "older" vehicles mean prior to 1990?? thats 30+ years ago! is your 4runner a 1990?? & the "damage" they mention is only if you run low on oil & dont check it!!! synthetic oil itself does NOT cause engine damage, einstein!

Tips for Using Synthetic Oils in Older Models
When using the term �€œolder�€� to refer to cars, it means those manufactured before 1990 or so. The risk with these models is that the seals, gaskets, and other components often aren�€™t as tight as with newer models. Because synthetic oil does a better job of cleaning out sludge, it could remove deposits that are acting as seals. This could result in leaks that cause the engine to burn oil and require you to monitor your oil levels and replace it more often. If you don't, you risk damaging the engine or other components.


It�€™s not accurate to say that you should never use synthetic oil in an older car. In fact, Castrol EDGE High Mileage is a synthetic oil designed specifically for high-mileage cars. If the car has been maintained and is in excellent running condition, the synthetic oil may protect the vehicle and prolong its life. Also, anytime you change from conventional oil to synthetic oil, always make sure to change the oil filter with every oil change.

Here we go again, lol. I've only had my runner for about 24k miles and I've run Valvoline Maxlife full synthetic 5w30 the whole time. I didn't bother asking the PO what they were running because I don't subscribe to the theory that you can't or shouldn't switch to synthetic. I run what I believe in. Doesn't matter to me what they ran in it. It has a very minor leak on the rh side of the engine that I honestly haven't taken time to diagnose. However, it was like that when I bought it and it doesn't appear to have gotten any worse. Also, I have 287k on it so a very minor leak doesn't bother me too much. One day when I have time I'll fix it. And when I say minor, I mean it's never enough to hit the ground and it doesn't seem to be causing the level to drop. It drops about 1/2 a quart between changes which I do every 5K. I never have to add between changes. With 287K I find that totally acceptable. I figure if it was a domestic vehicle it would be losing more than that by the time it had 75K on it, lol.

There’s a 4th possibility, switching back and forth between dino & syn. That’s not a planned thing necessarily but I’ve done it numerous times. The engine doesn’t obsess over this stuff the way we owners do.

Conventional...as recommended by the dealership.