What fuel do you run?

[ginkang]

87 here

Sometimes I use an 89 or 91 when I drive down to the states. ( I live in Canada). That is about 3 times oer year. With 87, my 4R runs great.

 

[LP_4Runner]

A lot of people get really confused about the whole octane thing with good reason. There are a LOT of myths surrounding it. The octane number only tells you that fuel's resistance to pre-detonation. In other words, its resistance to be ignited in the combustion chamber BEFORE its intended to be by the spark plug. The compression and heat of the combustion chamber can set the fuel-air charge off prematurely in an easier fashion with a lower-octane fuel.

Now, a lot of people have started to think that there is more inherent "power" in higher octane fuel. This simply isn't the case. The differences are in the additive package and are simply not really measurable in the real world power-wise. Where all this confusion came about was from those simple words: "for higher performance premium (91 or higher octane) fuel is recommended". People unfamilar with engine design and controls (as well as basic operation) simply started thinking that applied to all vehicles and meant premium fuel must have more "punch". Alas, no. The added performance comes only in engines which use knock sensors. With higher octane fuel, such engines can advance the ignition timing more before causing detonation (ping) and thus setting off the knock sensors. Thus, a performance increase.

The 4Runner has knock sensors for both the V6 and V8 engines, so in theory running higher octane can provide additional peak power. HOWEVER...I say in theory for a reason. The engine may be perfectly capable of providing peak power via maximum timing advance on regular octane gasoline. In that case, running premium gives no benefit at all.

 

[keylay31]

A lot of people get really confused about the whole octane thing with good reason. There are a LOT of myths surrounding it. The octane number only tells you that fuel's resistance to pre-detonation. In other words, its resistance to be ignited in the combustion chamber BEFORE its intended to be by the spark plug. The compression and heat of the combustion chamber can set the fuel-air charge off prematurely in an easier fashion with a lower-octane fuel.

Now, a lot of people have started to think that there is more inherent "power" in higher octane fuel. This simply isn't the case. The differences are in the additive package and are simply not really measurable in the real world power-wise. Where all this confusion came about was from those simple words: "for higher performance premium (91 or higher octane) fuel is recommended". People unfamilar with engine design and controls (as well as basic operation) simply started thinking that applied to all vehicles and meant premium fuel must have more "punch". Alas, no. The added performance comes only in engines which use knock sensors. With higher octane fuel, such engines can advance the ignition timing more before causing detonation (ping) and thus setting off the knock sensors. Thus, a performance increase.

The 4Runner has knock sensors for both the V6 and V8 engines, so in theory running higher octane can provide additional peak power. HOWEVER...I say in theory for a reason. The engine may be perfectly capable of providing peak power via maximum timing advance on regular octane gasoline. In that case, running premium gives no benefit at all.

Thanks for the explanation, but what's your conclusion?

 

[khaug]

I use 93 octane when I tow with our '03 V8, and 89 the rest of the time.

If I run 87, there is noticable rough running on moderate acceleration, which is due to the knock sensor retarding the timing. This can happen with some brands of 89, but has never happened with 92-93 premium. The roughness isn't pronounced in any event, but the V8 is so gorgeously smooth at its best, I'm willing to pay the .10c/gal to preserve that.

 

[LP_4Runner]

My conclusion would be that pretty much each person would have to experiment a little and use the fuel which makes them comfortable. I've seen two of the exact same engine run differently with the same fuel. One might knock/ping and have retarded timing with 87 octane and the other run perfectly fine. There are so many slight tolerance differences that making a blanket statement is rather hard to do.

I can say that the older the engine the more all this comes into play. Carbon build-up in the combustion chamber makes older engines more susceptable to knocking with lower-octane fuel.

 

[007Runner]

Toyota is now recommending 87 octane period. If a greater octane is required or needed, don't you think the manufacturer of the engine would tell you? In 2006 Toyota specified premium for increased performance. The 2007 engines, the V6 and V8 did not change. Yet Toyota removed the recommendation for higher octane. Perhaps Toyota did further testing and discovered there was no increased performance. If you are pinging or not running well on 87, chances are the gas is in poor condition or the quality of the fuel is bad.

 

[LP_4Runner]

Actually you don't know if anything changed. Manufacturers rarely advertise or publicize ECU changes which aren't directly related to problems or don't provide features customers will readily notice. You could take 10 sample vehicles from over an entire model year and its entirely possible for each one to have a different ECU software version. I have seen this, and for the most part it makes no difference at all. Slight fuel map tweakings, algorithmic changes, etc.

Now, all that said, I've also seen owner's manuals change to recommend only 87 octane for political reasons too. Regular unleaded is cheaper than premium and saying you only ever need regular to get maximum performance reduces the perceived cost of ownership.

As I said before, carbon build-up can be a major cause of knock/ping with regular fuel on higher mileage engines (or engines exposed to environments which can accelerate carbon accumulation). Bad fuel rarely is a root cause for TRUE knock or ping - its symptom is usually just rough running (due to contaminants in the fuel - primarily water and sediment).

So overall, its up to the owner. If the vehicle seems to run better on premium, then use premium. If it runs acceptably on regular, then by all means save the money. The ECU in the 4Runner is not in any way calibrated on a high-performance curve so even if there is a slight timing advance advantage to using premium over regular, I highly doubt it would create enough of a difference for anyone to truely FEEL a performance difference (though many people will trick themselves into thinking they do psychologically - like with some mods which provide +3 or +5 hp...a person is not going to FEEL that in reality on a 4000+ lb vehicle). In fact, yes...this may even be another reason (as mentioned) that Toyota stopped adding that part to the manual. Whatever performance difference may not have even been realistically noticable to a real-world driver.

 

[Boston_Runner]

All the V8 4runners and GX prior to 06 stated in the manual that 87 is recommanded but use 91 for improve performance. The 07 4runner now say use 87 only and the 07 GX's manual states, use 91 or higher only. Both V8 are identical, I am wondering if there is indeed a ECU diff. or is it motivated by politcal reasons.

 

[LP_4Runner]

Actually the GX specs are slightly different. Compression ratio is bumped from 9.6 to 10.0 (which explains a lot about requiring 91 octane or greater). Horsepower is listed as 263 peak vs the 4Runner's 260 peak. Peak torque output is 323 vs 306 for the 4Runner. However, the GX is significantly more heavy and with that factored in the 4Runner is going to feel a bit more "peppy".

 

[Chicago-Spike]

Wow, the same threads here as on the motorcycle board. Octane rating has nothing to do with better performance. Use what the manual states, 87 from what it sounds like, unless you hear the engine ping then go up one level. "Premium" does NOT mean "Best". The rating has to do with how fast the fuel burns in the combustion chamber.

This is from my motorcycle board and one of our best mechanics.

One of the most frequently misunderstood issues among the VTX community, and indeed among all folks concerned with performance and appropriate care and feeding of their motors is the subject of gasoline, and more specifically the mysterious octane number. Oil companies have gone a long way to foster this mystery, by marketing gasoline with higher octane numbers as

 

[keylay31]

I read the whole thread so here's the question:

In Colorado, the 'regular' octane is 85 and this is similar to 87 (midrange here) in other lower level locations.

If a vehicle needs lower octane at altitude, is the 85 here in Colorado the 'same' as 87 elsewhere?

The local dealership recommends 87 midrange octane.

Can I use the local 'regular' 85?

Any experiences?

I bought my T4R from a dealer here in CO and according to him, 85 octane is plenty good here in CO because of some (elevation?) issues. It's cheaper, and from everyone's conclusions, it seems that the effect of premium is just percieved. I think I'll go with what Toyota has printed, what the dealer recommends, and what is cheapest.

Does this not make sense to anyone?!!?

 

[Chicago-Spike]

I bought my T4R from a dealer here in CO and according to him, 85 octane is plenty good here in CO because of some (elevation?) issues. It's cheaper, and from everyone's conclusions, it seems that the effect of premium is just percieved. I think I'll go with what Toyota has printed, what the dealer recommends, and what is cheapest.

Does this not make sense to anyone?!!?

That is exactly what you should do. Rode my bike out there in Colorado the last 2 July's, my bike LOVED the 85. I got about 5mpg better mileage on that stuff.

 

[CrawFish]

2005 SE, I run 89. Does anyone else notice the rotten egg smell reduces when you run high octance? I use to run 87, but I can't that sulfur smell. Then I switched to 93 and it went away. Then I switched to 89 to see what happens, I only smell it under heavy excelleration.

 

[kanadakid]

Learned a lot !

I have read this entire thread and have learned a lot. I know some of you guys have said that this topic has been beat to death but having just bought a new 4Runner it was of great interest to me.


Some fo you guys reakky know your stuff and the information has been really helpful.

At the end of the day the current 4 runner maunal reccomends 87 ocatne rating and after reading all of the information see no reason to deviate unless I'm towing a heavy load in very hot weather.........


Thanks

Kid

 

[Chicago-Spike]

After rereading my post on this, I seem to have forgotten that a car/truck ECU operates differently from a bikes. The car/truck ECU(and some bikes) have the ability to advance/retard the ignition as well. This gives the engine the ability to use the mid-grade and premium fuel and not have a detrimental affect on the operation of the engine. Sorry for the mis-information

 

[mtnracer]

When I bought the truck I always used 93 Amoco (from Costco) but when gas prices spiked I started using 87 (Amoco).

I gotta say that I definitely noticed a performance drop using 87 in my 2003 V8 Runner.

On 87 the tranny downshifts much sooner when passing at highway speed. On 93 the truck pulls smoother and stronger in most situations.

Anyone here claiming there is no difference needs to run the 87 to empty and then fill up with 93. You'll feel it right away - at least in a non VVTi V8.

 

[gRunner3]

I haven't noticed any difference in shift timing, but I do think the car is running a tad quicker using 93. I have been using 87 for the entire first year and half I've had my car and just recently (about 3 months ago) switched to premium after crunching the numbers and realizing how little the difference was in cost.

The biggest thing I've noticed is a lot less stink. I know this isn't just in my head because I could make my car stink at will using 87 octane, and now I have a hard time getting it to do that even if I try. When I used 87 octane, I sometimes used cheap places and sometimes used Top Tier depending on where I was when I needed to fill up. Now that I'm using premium I am only using Top Tier.

As I mentioned, there may be a slight performance difference but the biggest thing is the lack of sulfer stink.

 

[iLLWiLL]

what is "knocking"? Is it a sound that is heard, if so, when?

 

[BassMiesterNJ]

My last (6) tanks have been Sunoco 87 regular.

IMO, runs the same and there is a big price difference jumping up to 89, 91 or especially 94.

So if it runs ok, why not ?

 

[michael90630]

I use Chevron Techron 87.

2007 T4R SR5 V6 4WD