Gas grades, Premium vs. Regular comparison notices

[RUN-4-LIFE]

Back ground - bought my 07 SR5 4WD at a dealer with roughly 86k miles. Driven roughly 20k miles since ownership last January, have run only premium grade gasoline

Now I am averaging 15.5mpg city 19 to 20mpg highway (sometimes 21-22 with tail wind) usually between 17 - 18mpgs mixed. This is on premium, I don't use the computer I calculate my own mileage, cause for some reason it only does lifetime averages... ( thanks Toyota)

Was out in the sticks needing gas stopped at a local gas station to my total first world problem I found out that they only have regular gasoline. GASP!!!! In need of gas I said whatever and filled up.. Driving home I had a thought, kind of a small experiment, use regular for about 1k miles and check my results for MPG and see if the extra $.50 to $.75 a gallon is worth it.

Driven roughly 600 miles two tanks of gas and have found out that I've lost mileage per gallon. The loss isn't drastic 14 city driving and 17 to 18 highway.. That combines to about 16 mixed. So I've lost about 40 miles per tank..

I've also noticed a little less pep in the truck, it still gets up and goes just not the manner with premium.. But that cannot be tested without proper timing equipment.

Not a promotion for using premium instead of regular, this just happened. Decided to share current results.

Testing gas mileage every couple days.. Mainly filling Sunday, and Friday.. Do city driving weekdays and my highways weekend. Just a thought has anyone noticed difference in gas mileage in their trucks between premium and regular?

Zack

 

[07V8]

I too notice better performance and mileage with 93. I typically run 89. The gas stations that I use are mainstream but I'm not confident they move substantial volume of 93. I've filled up and its been stale so I stick with 89.

 

[V6Mike]

I don't run premium, only regular ('08 V6 SR5). But, I make sure to try and buy only Top Tier gas. On another note, the FJ with the same V6 engine specifies premium...Why?

 

[Bluesky 07]

Science says that absent special circumstances, using higher octane than recommended by the manufacturer is simply wasting money. If your engine isn't knocking on 87, you don't need anything higher. I'm betting the performance difference you noticed is because it's what you were expecting to happen.

It's no coincidence that few, if any, carmakers recommend 89 octane. So why do oil companies make it? Because research shows that given two pricing options, consumers usually pick the less expensive, but when offered three, they tend to choose the middle one. So it's just a way for the oil companies to get 10-20 cents more a gallon for absolutely no benefit.

Look, I'm not judging - I do the same thing with oil, spending extra to use synthetic when I know deep down that any benefit over the dino Supertech at Walmart is likely marginal at best.

I guess we all have our superstitions but if you're paying the diff between 87 and 93 every time you fill up, you're pumping a lot of cash through your truck that you could be using on other things,.

 

[07V8]

I don't run premium, only regular ('08 V6 SR5). But, I make sure to try and buy only Top Tier gas. On another note, the FJ with the same V6 engine specifies premium...Why?

Gasoline sold in the US has to meet federal specifications. Branded gas simply adds their own detergent and call it something unique. The reality of it is there are less than a handful of mainstream companies that provide detergents to the suoermajors. All detergents are essentially identical.

Another fun fact is Exxon gas does not mean it came from an Exxon refinery or well. Same with BP, Shell, Chevron etc. It's all shipped on pipelines and blended at terminals. It only becomes "brand" gas when they squirt the bottle of detergent in the tanker truck. Literally.

 

[Freyer]

Gasoline sold in the US has to meet federal specifications. Branded gas simply adds their own detergent and call it something unique. The reality of it is there are less than a handful of mainstream companies that provide detergents to the suoermajors. All detergents are essentially identical.

Another fun fact is Exxon gas does not mean it came from an Exxon refinery or well. Same with BP, Shell, Chevron etc. It's all shipped on pipelines and blended at terminals. It only becomes "brand" gas when they squirt the bottle of detergent in the tanker truck. Literally.

I completely agree. The only benefit of going with a larger brand name station is that they typically turn over their gas quicker, so you are less apt to get gas that has deteriorated due to age. In my runner I'll go to whatever gas station is cheaper. In my subauru I tend to go to the brand names just to make sure I am getting fresh gas (and of course they have well maintained pumps that accurately mark the octane).

 

[RonJR]

I haven't had my '06 long enough to have run valid comparisons, but my '94 definitely runs better and gets about 5% better mileage on midgrade vs the lowest octane grade. Here's why:

All modern computer controlled engines have knock sensors. The ECU advances timing until the onset of light (inaudible and non destructive) pinging and keeps it there. The higher the octane fuel, the further the ECU can advance the timing. All else being equal, advancing the timing extracts more energy from the fuel charge, increasing power and/or improving mileage.

On my '94, I go from averaging about 18mpg on 85 octane to 19 on 87 (these octane numbers are for the high altitude in Colorado. Equivalent to 87-89 for you lowlanders.) The increase in power is noticeable, and the 3.0 liter V6 needs all the help it can get. Since the extra cost is partially offset by the better mileage, I choose to run midgrade in the '94.

As I've said, the jury is still out on the '06. Obviously the V8 is not power challenged, so that won't be a factor in my ultimate decision.

Please note there is no harm in running a computer controlled engine on low octane fuel. The ECU will simply adapt to the fuel by dialing back performance. Toyota specs midgrade for the 4th gen 4runners because they get better horsepower and EPA numbers than if they had used the lowest octane.

 

[RUN-4-LIFE]

I don't run premium, only regular ('08 V6 SR5). But, I make sure to try and buy only Top Tier gas. On another note, the FJ with the same V6 engine specifies premium...Why?

Wonder if the FJ is higher compression... Mhmm time to google

 

[KidVermicious]

Oh FFS. :ybrick:

How can we be in the 21st century and still have so few people who understand what the hell octane in gasoline is for?

 

[RUN-4-LIFE]

Science says that absent special circumstances, using higher octane than recommended by the manufacturer is simply wasting money. If your engine isn't knocking on 87, you don't need anything higher. I'm betting the performance difference you noticed is because it's what you were expecting to happen.

It's no coincidence that few, if any, carmakers recommend 89 octane. So why do oil companies make it? Because research shows that given two pricing options, consumers usually pick the less expensive, but when offered three, they tend to choose the middle one. So it's just a way for the oil companies to get 10-20 cents more a gallon for absolutely no benefit.

Look, I'm not judging - I do the same thing with oil, spending extra to use synthetic when I know deep down that any benefit over the dino Supertech at Walmart is likely marginal at best.

I guess we all have our superstitions but if you're paying the diff between 87 and 93 every time you fill up, you're pumping a lot of cash through your truck that you could be using on other things,.

I have only ran regular for two tanks 600 miles and have noticed a small difference in performance. Not drastic but it's less peppy. No I didn't go in expecting, just interesting to see.

As far as oil, I'm under extended warranty so the dealer does my oil change for Dino oil. But when my extended expires I will be doing my own oil changes again. And mobile 1 synthetic with Toyota filter or Bosch depending on if I want to make an extra trip to the dealer. But Dino oil change at my dealer is about 30 bucks, oil change myself about 35 but I use better oil and know it's done properly. I also like turning a wrench. I have trust issues with my car.

If higher octanes burns cleaner and keeps the engine cleaner for the life of it I'd spend extra. I don't know about you guys but I've owned two cars in my life a Chevy Avalanche and this 4Runner and drove the Avalanche 2002 until the heads cracked and the exterior was falling apart 260k miles. A lot of rust. Plan on running the 4Runner into the ground also, I'll spend more now to keep it running longer later.

My thought process.

 

[RUN-4-LIFE]

Oh FFS. :ybrick:



How can we be in the 21st century and still have so few people who understand what the hell octane in gasoline is for?

I ask the same about economic theories. But then again everyone has their interests.

Octane in the basic definition is just the engines ability to resist knocking.

 

[Gatafly]

I have only ran regular for two tanks 600 miles and have noticed a small difference in performance. Not drastic but it's less peppy. No I didn't go in expecting, just interesting to see.

As far as oil, I'm under extended warranty so the dealer does my oil change for Dino oil. But when my extended expires I will be doing my own oil changes again. And mobile 1 synthetic with Toyota filter or Bosch depending on if I want to make an extra trip to the dealer. But Dino oil change at my dealer is about 30 bucks, oil change myself about 35 but I use better oil and know it's done properly. I also like turning a wrench. I have trust issues with my car.

If higher octanes burns cleaner and keeps the engine cleaner for the life of it I'd spend extra. I don't know about you guys but I've owned two cars in my life a Chevy Avalanche and this 4Runner and drove the Avalanche 2002 until the heads cracked and the exterior was falling apart 260k miles. A lot of rust. Plan on running the 4Runner into the ground also, I'll spend more now to keep it running longer later.

My thought process.

There is absolutely no difference in cleaning ability between gas grades. Only difference is octane and octane numbers correlate to engines compression and ability to resist knocking. High performance (high compression) engines need high octane to resist preignition which degrades performance and can cause engine damage over time. Unless you are towing heavy weights and/or doing so at higher altitudes there is zero benefit to paying more for premium gas. You engine will adjust its timing to run like it should and the small increase in mileage does not come close to the price difference.

 

[07V8]

There is absolutely no difference in cleaning ability between gas grades. Only difference is octane and octane numbers correlate to engines compression and ability to resist knocking. High performance (high compression) engines need high octane to resist preignition which degrades performance and can cause engine damage over time. Unless you are towing heavy weights and/or doing so at higher altitudes there is zero benefit to paying more for premium gas. You engine will adjust its timing to run like it should and the small increase in mileage does not come close to the price difference.

You're incorrect. Premium grades of gas (91-93) typically have twice the detergent than regular.

 

[RUN-4-LIFE]

There is absolutely no difference in cleaning ability between gas grades. Only difference is octane and octane numbers correlate to engines compression and ability to resist knocking. High performance (high compression) engines need high octane to resist preignition which degrades performance and can cause engine damage over time. Unless you are towing heavy weights and/or doing so at higher altitudes there is zero benefit to paying more for premium gas. You engine will adjust its timing to run like it should and the small increase in mileage does not come close to the price difference.

That's what I've heard. I don't mind spending extra at the pump, I've never ran regular regularly in my 2 vehicles. Don't plan on doing so, I could be putting that extra 75 cents per gallon to worse use.... LikePumkin spice lattes... ugh. White women.

 

[Gatafly]

You're incorrect. Premium grades of gas (91-93) typically have twice the detergent than regular.

Your right, I stand corrected. After a quick search it seems the concensus is that the extra detergents are a waste as there is more than enough detergents in regular gas. They do say Top Tier gas is more an advantage than regular premium which makes sense.

 

[bamma]

Get gas at Costco. It is top tier and cheap. Not sure about the 4runner, but my Tacoma ecu adjusting timing and power based on the octane of the gasoline. Many modern engines have variable ignition timing.

It is true with older engines that running a higher octane than recommended makes no difference and is a waste of $$$.

 

[RonJR]

Science says that absent special circumstances, using higher octane than recommended by the manufacturer is simply wasting money. If your engine isn't knocking on 87, you don't need anything higher.

This was true back in the days of carbureted engines with no closed loop mixture and timing control, but it's not true today. The major things that affect whether or not an engine will knock are compression ratio and ignition timing advance, and somewhat less the mixture. For any given engine the compression ratio is of course fixed, but the timing and mixture are under complete control of the ECU. The ECU will adjust timing to keep the engine just at the edge of knocking, even if you're running really low-grade gas. Your engine just won't have as much power as it will on higher octane.

There's a pretty significant hill on I-25 in northern Colorado just south of the Berthoud exit, probably a 4-5% grade for a mile and a half. On 87 octane, my '94 4Runner will hold 70mph in 5th gear on that hill. With 85 octane, I have to shift to 4th to maintain 70. It's a clear difference, as is the fuel mileage.

A higher octane rating does not provide the gasoline with more intrinsic energy, but it does allow the engine to extract more energy from that gasoline by running at a higher efficiency.

 

[KidVermicious]

Sorry, Ron, but you're fooling yourself. Lots of modern trucks are smart enough to adjust ignition advance on the fly, your '94 is not one of them. It has a knock sensor, and will severely retard timing and go into limp mode if it detects knock, but it is designed for regular gas and assuming everything else is working correctly, will not go any faster with higher octane fuel. And if your knock sensor was triggering a limp mode, you wouldn't be able to hold 70 on a flat at sea level, let alone climbing a grade at 5000 feet.

Here's the deal, guys. The only thing octane in gasoline does is help prevent preignition, or engine knock. That's ALL it's there for. When the air/fuel mix is compressed by the closing piston, the heat generated by the rapid compression can cause the mix to ignite early. If that mix detonates before the piston begins to open again, Bad Things (TM) happen. So octane is added to your gasoline to ensure that the air/fuel mix ignites when the spark plug tells it to and not earlier. Now - in high performance motors, advanced ignition timing or higher compression levels require more octane to prevent early detonation, which is why some vehicles specify premium fuel only. But the octane itself does not make a bigger boom, it doesn't clean any carbon, higher octane fuels don't do you any good at all unless your motor is designed/tuned to take advantage of them. Many (most?) modern powerplants are smart enough to adjust ignition depending on what octane you last filled up with, so you can run regular or premium and it might SEEM like the premium is better gas because you get a little more power and a little better MPG, but it's not the gas. It's your motor, taking advantage of the extra octane to play with the ignition timing and squeeze a little more performance out of your motor.

I'll let a smart guy like [MENTION=66389]BlackWorksInc[/MENTION] tell us if the 4th gen powerplant is one of those that's smart enough to adjust ignition timing on the fly. But if you've got a motor that isn't designed to take advantage of the higher octane levels in premium fuel (like RonJRs 3VZE), then buying premium fuel is literally throwing your money away.

 

[Ralph Blake]

It's the alcohol in any gasoline that i feel causes problems, when i can't get real gas i always notice a drop in gas mileage.
Lately since the drop in the crude price, i have noticed it's getting hard to find real gas and also 89 octane gas. Just regulator 87.
Maybe where you'r at you have everything real gas and 91 octane.

 

[RonJR]

Sorry, Ron, but you're fooling yourself. Lots of modern trucks are smart enough to adjust ignition advance on the fly, your '94 is not one of them. It has a knock sensor, and will severely retard timing and go into limp mode if it detects knock, but it is designed for regular gas and assuming everything else is working correctly, will not go any faster with higher octane fuel. And if your knock sensor was triggering a limp mode, you wouldn't be able to hold 70 on a flat at sea level, let alone climbing a grade at 5000 feet.

You are simply wrong about this. The Toyota technical training material for the OBD I engines (among them the 3vze) states "The Knock Sensor detects engine knock and sends a voltage signal to the ECM. The ECM uses the Knock Sensor signal to control timing." This has been true ever since Toyota introduced multiport, computer controlled, fuel injection.

The '94 has a diagnostic data stream that comes from the ECU via the diag port. With a little bit (OK, a lot) of programming, you can read that data stream and see, among other things, what the ECU is doing to ignition timing as engine load and rpm vary. It's obvious the ECU knows all about the ignition timing, and is in complete control of it. There is no open-loop vacuum or centrifugal ignition advance such as we had on older engines. It's all done by the ECU.

I have studied the 3vze engine control system in detail for the past 5 years. I'm not guessing here, I know I'm correct on this.

Here's the deal, guys. The only thing octane in gasoline does is help prevent preignition, or engine knock. That's ALL it's there for. When the air/fuel mix is compressed by the closing piston, the heat generated by the rapid compression can cause the mix to ignite early. If that mix detonates before the piston begins to open again, Bad Things (TM) happen. So octane is added to your gasoline to ensure that the air/fuel mix ignites when the spark plug tells it to and not earlier. Now - in high performance motors, advanced ignition timing or higher compression levels require more octane to prevent early detonation, which is why some vehicles specify premium fuel only. But the octane itself does not make a bigger boom, it doesn't clean any carbon, higher octane fuels don't do you any good at all unless your motor is designed/tuned to take advantage of them. Many (most?) modern powerplants are smart enough to adjust ignition depending on what octane you last filled up with, so you can run regular or premium and it might SEEM like the premium is better gas because you get a little more power and a little better MPG, but it's not the gas. It's your motor, taking advantage of the extra octane to play with the ignition timing and squeeze a little more performance out of your motor.

Which is exactly what I said.