Is 91 octane really over kill on a 3rd gen?

[nc-grayson]

Different tuning. The Land Cruiser was designed to be driven in places where premium isn't an option. The Lexus has US specific tuning in the ECU to meet EPA requirements, so it wasn't a concern.

They'll both run fine on 87, they just won't run as much timing advance, which means less power.

Good info here, thanks Jeremy!

 

[nc-grayson]

And to keep it on topic and 3rd gen related, I'll add my $.02

Pressing the ECT power button will net you more mpg's than any premium fuels, and it's free.

 

[pluton]

Will racing gas make five foot flames come out of the exhaust pipe right when I start the car?

 

[ShooterMcGavin]

Will racing gas make five foot flames come out of the exhaust pipe right when I start the car?

Yes, but only if you are double-clutching like you should, not granny shifting! Couple more tips on that note: NOS helps and Winning's winning!

https://www.youtube.com/watch?v=pB-bN-RkJLM

 

[JayRolla]

Will racing gas make five foot flames come out of the exhaust pipe right when I start the car?

High flow exhaust. Rich tune. Remove the blow off valve recirculation tube which causes rich shifts. Fire balls every time.

 

[4racer]

Must be a huge price difference in 91 vs 87 for some of you. I see a max of .20 cent difference. On the average of 14 gallon fill up, were at 2.80 extra for 91. If you see a 1 mpg increase, then you've essentially gotten an extra 14 miles, which equates to one gallon of gas or roughly 2.80. So it looks like I balances out.

So if you like running 91 then go ahead. If you don't, not harm done. Every car I own takes 91 and I simply do it out of habit now.

 

[jeremyc74]

Must be a huge price difference in 91 vs 87 for some of you. I see a max of .20 cent difference. On the average of 14 gallon fill up, were at 2.80 extra for 91. If you see a 1 mpg increase, then you've essentially gotten an extra 14 miles, which equates to one gallon of gas or roughly 2.80. So it looks like I balances out.

.

I think you're missing the point. If the ethanol content is equal between the two grades, there's absolutely no reason you're going to get better mileage with the higher octane. It doesn't have more energy content, it just has additives that make it harder to ignite. There isn't a mileage gain to be had by using it.

 

[ThorInc]

I actually run Shell 91 in my truck and bass boat because it's ethanol free. There is a significant milage gain in the 2 stroke v6 but not so much in the 4runner.

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[I_bRAD]

Down here they all have it, but we don't have seasonal blends so maybe that's the difference.

The ethanol has less energy content (but higher octane), so there's no doubt that pulls mileage down. If they're using different level of ethanol in the different grades that would certainly explain why some people are getting better or worse mileage depending on what they're buying.

My car gets worse mileage than the 4Runner on the E85. With a 13 gallon tank that's a real pain in the ass. :fish:

All of my other cars take super so I've never tried the experiment on them. Incidentally, I just noticed your location- my 740 turbo spent the first 8-9 years of it's life in Palm beach! It's a long way from there now (and still running strong on super.)

 

[I_bRAD]

I actually run Shell 91 in my truck and bass boat because it's ethanol free. There is a significant milage gain in the 2 stroke v6 but not so much in the 4runner.

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Weird. AFAIK Shell and Ultramar are the only ones without ethanol in the super. What are you comparing super shell against? My experiment was mid grade ultramar vs super. Would be interesting to know if Shell puts in less ethanol, or maybe it's even a regional thing.

 

[ThorInc]

Weird. AFAIK Shell and Ultramar are the only ones without ethanol in the super. What are you comparing super shell against? My experiment was mid grade ultramar vs super. Would be interesting to know if Shell puts in less ethanol, or maybe it's even a regional thing.

In Ontario, Shell V-Power is definitely 100% ethanol free. Likely Ultramar Super as well but I stick with Shell as it became a habit when filling the bass rig. For peace of mind, I run Shell Nitro in damn well everything as a precaution. I am comparing it to Petrocanada, Esso, etc. premium fuels. I also get really good mileage in the boat on 94 but that has 10% ethanol so I would run ringfree with two full tanks. I run no additives usually with the Shell V Power other than in the Fall.

 

[Porqupine82]

I use to deliver Pizza's in a 1994 Acura Integra GSR.

Using regular I would get about 21 MPG.
With premium, I would get 26 MPG.


All that to say, it does make a difference.

However, I don't plan on using it in the 4runner. Simple engine.

Lol... a B18 is a simple engine. Perhaps even more so.

I used to drive a jdm type R B18c, with b16b pistons, and 14 lbs of boost... now THAT needed 93 octane.

 

[jhfleet]

It's interesting to read about perceptions about gasoline. I always figured T4R owners were knowledgeable about such stuff, but maybe not all of us. Bottom line is that engines designed to require higher octane fuel might lose a little power and mileage when using 87 octane because the ignition retards to avoid spark knock. If the knock sensor never senses detonation on regular fuel, using higher octane fuel is a complete waste of money. The 3.4 is setup to run on regular, so it's likely to gain little or no benefit from using a higher octane. I've never seen any measurable difference when using higher octanes in my T4R, and I actually get higher mileage using regular in my commute car, which is supposed to use 93 octane. BTW, I don't share the gasoline brand loyalty expressed by others. In most parts of the US a single company's refinery supplies all stations regardless of brand. Each branded station adds a proprietary additive to the fuel storage tank, but the base gasoline is the same at all stations.

 

[pluton]

In most parts of the US a single company's refinery supplies all stations regardless of brand. Each branded station adds a proprietary additive to the fuel storage tank, but the base gasoline is the same at all stations.

This is well-known to those who's only source of info isn't TV commercials. I think it was covered on "Modern Marvels" on the History Channel way back over ten years ago.
Btw, it's the same or similar situation with most name brands of motor oil.

 

[CDNsldr]

Spark plug design also plays a significant role in the whole octane debate. Plugs are designed to operate at a very specific temperature. Using a "cooler" plug may not fully, or instantaneously ignite all of the air/fuel mixture in the combustion chamber, much like runner a higher octane with plugs designed for a lower octane may not fully burn the mixture.

 

[TimeZone]

Its habit for me to run 91, Both my BMWs runs alot better with it, so screw it mays well run it in the 4Runner too. My mother ran a service station for 30 years, did the same commute for that time with Jeeps. Tried 87 vs 91, and each week it would cost about 20 bucks extra with regular because it would burn more. Just my experience

 

[Focoty]

I know this thread is dedicated more towards naturally aspirated vehicles but I just wanted to give a quick PSA to those with superchargers that wonder whether or not they can get away with running less than premium fuel. When I first bought my supercharged truck they filled my tank as a "courtesy" with low grade fuel. Through the course of that tank the car ran like crap, I had pinging, and averaged like 16 mpg with a mix of highway/city driving. I ran that completely empty and filled up with 91 and it made an entire world of difference. It ran as smooth as can be, basically no pinging, and I actually averaged nearly 20 mpg with almost identical driving habits from the last tank. Granted like I said before this doesn't really apply to the NA vehicles, as they are built to be able to run on low octane.

 

[PWD4R]

Its habit for me to run 91, Both my BMWs runs alot better with it, so screw it mays well run it in the 4Runner too. My mother ran a service station for 30 years, did the same commute for that time with Jeeps. Tried 87 vs 91, and each week it would cost about 20 bucks extra with regular because it would burn more. Just my experience

Idk about $20 extra. Maybe on fuel from 30 years ago. There are so many additives nowadays


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[3bears]

And to keep it on topic and 3rd gen related, I'll add my $.02

Pressing the ECT power button will net you more mpg's than any premium fuels, and it's free.

I agree on this, but I live in the mountains. I had noticed that I got better mpg with plus or premium, but now that I use the ECT I have increased my mpg slightly.....regardless of octane numbers. I now avg 20 to 21 on plus (mid grade), but the power curve is much better for the mountains with the ECT

 

[Falonious]

I know this thread is dedicated more towards naturally aspirated vehicles but I just wanted to give a quick PSA to those with superchargers that wonder whether or not they can get away with running less than premium fuel. When I first bought my supercharged truck they filled my tank as a "courtesy" with low grade fuel. Through the course of that tank the car ran like crap, I had pinging, and averaged like 16 mpg with a mix of highway/city driving. I ran that completely empty and filled up with 91 and it made an entire world of difference. It ran as smooth as can be, basically no pinging, and I actually averaged nearly 20 mpg with almost identical driving habits from the last tank. Granted like I said before this doesn't really apply to the NA vehicles, as they are built to be able to run on low octane.

Yup...with a SC we are stuck with premium whether we like it or not. Truck ran perfect with regular before SC install.