Is everyone running 87 Octane in 2010 4Runner?

[luv2eat]

Here's my .02. Many high end cars require or recommend 91 or better octane. If you go overseas especially in Asia, many countries over there only sell 85 and/or 87 octane. These luxury high end vehicles are sold and driven in these countries without any modifications to the fuel system. My point.... it doesn't matter; it's a waste of $$$ putting in 91+ octane in the 4Runner. For those people who say that they notice better performance with 91+ octane, it's psychological. Now if you put avgas (100+), you'll definitely notice the performance until you mess up your engine 91 or better was "recommended" in my G35 but I've never noticed the minute difference in performance when I fed it 87 octane, though I would fill up with super majority of the time (because I loved that thing). Our GL requires 91 or better but I sometimes feed it 87; no difference in performance. Onboard computers adjust for these things anyways. If you own a real high performance car and it requires 91 or better octane, then I would definitely feed it 91+. From my limited knowledge, these high performance engines need the higher octane because the higher octane fuel burns cooler than the lower octane fuel. That's also why on hotter days, higher octane fuel will perform better. However, the 4Runner won't really notice a difference IMO. I'd save your money and buy yourself a Starbucks!
I had a Toyota Supra once that knocked and pinged unless I fed it super unleaded but it definitely had some engine issues.
As someone stated here before, it's more important on the quality of the gasoline. Stay away from the "cheap" gas which tend to contain more ethanol than good quality gas. My parents owned a gas station growing up, so I know a thing or two about quality gas vs. cheap gas.

 

[JB.]

How would you guys explain this sentence from the 4th gen manual. Does anyone know if there is any such wording in the 5th manual?

"For improved vehicle performance, the use
of premium unleaded gasoline with an
Octane Rating of 91 (Research Octane
Number 96) or higher is recommended."

 

[SeattleMike]

How would you guys explain this sentence from the 4th gen manual. Does anyone know if there is any such wording in the 5th manual?

"For improved vehicle performance, the use
of premium unleaded gasoline with an
Octane Rating of 91 (Research Octane
Number 96) or higher is recommended."

From page 613 of the 5th Gen Manual:

Fuel type Unleaded gasoline only
Octane rating 87 (Research octane number 91) or higher
Fuel tank capacity 23.0 gal. (87.0 L, 19.1 Imp. gal.)

Edited to add...

From page 623:

You must only use unleaded gasoline in your vehicle.
Select octane rating 87 (Research Octane Number 91) or higher. Use
of unleaded gasoline with an octane rating lower than 87 may result
in engine knocking. Persistent knocking can lead to engine damage.
At minimum, the gasoline you use should meet the specifications
of ASTM D4814 in the U.S.A. and CGSB3.5-M93 in Canada.

 

[SeattleMike]

If I remember it correctly is Page 413

I looked and 413 covers the interior lights. Could you double check? I'd really like to get that information.

 

[jreiter]

Seriously folks, the only way this octane debate is going to be proven is for someone to hook up an OBD scanner/logger to their 5th gen 4runner and do some testing with different types of gas.

• If higher octane does indeed make a difference, then the data logs will show the engine timing running more advanced with higher octane than with lower octane.
• If the logs show no difference in timing, then higher octane provides no benefit over lower octane. This would suggest that running lower octane still allows the engine to run at full timing advance, thus negating any benefit of higher octane.

Keep in mind that if you do this testing over the winter while temperatures are cooler, you'll probably get different results than if you test during the summer heat. My 1999 Tacoma is a good example of this. I *did* do this testing on my Taco:

• During the winter, 89 and 91 octane showed no timing advance over 87 octane.
• During the summer, 89 octane did show a slight timing advance over 87 octane during hot, 90+ degree days.
• Additionally, 91 octane showed no advance over 89 octane in the summer, suggesting that 89 octane allowed my Taco to run at full advance in the summer. This means that 91 octane was a waste in my 1999 Taco.

Also keep in mind that the timing benefits with higher octane only occurred during heavy-to-full throttle. I was not able to show any consistent differences in timing while simply cruising on the highway.

 

[jreiter]

I should also mention that I did similar testing in my 2000 Audi A4 with the 1.8 liter turbo motor. In that motor, octane did indeed make a *huge* difference. I had that motor significantly modified, though, with a slightly larger turbo and significantly more boost (18 psi instead of the factory 8 psi). In that car, even with 91 octane the computer was constantly battling the knocking and falling back the timing on hot days. There was no way I could run less than 91 octane in that car without risking blowing the motor up.

I know mentioning the Audi is like comparing apples to oranges here, but I thought it was good to mention since it shows that octane *can* make a (sometimes huge) difference in the right conditions. Do I think it makes a difference in the new 4runner? I can't say, but I will do this testing once I get my own 5th gen.

It's interesting to note that the 5th gen 4runner uses 10.4:1 compression pistons, which is somewhat high for a typical truck motor. The Tacoma motor uses 9.6:1, I think. (?) That explains the lower power in the Tacoma, even though they otherwise use the same 4.0 liter motor. However, it also makes the Tacoma more resilient to low octane knocking than the 4runner. Figured I'd throw that in there even though it's obviously speculation on my part.

 

[SunPilot]

Running a higher octane gas than required can also contribute to the build up of engine deposits from incomplete detonation that will eventually gunk up your motor and rob it of power, performance, and efficiency.

I generally point, laugh, and shake my head at folks who use an improperly high octane on their vehicle. They are throwing money away in more ways than one.

Incidentally, when I filled up in Flagstaff, AZ, their regular unleaded was an ultra-low octane of 85. I was concerned about this until I learned that lower octanes are required when your automobile is operating at higher altitudes. Less O2 at altitude means less risk of detonation and less need for higher octane. You learn something new everyday.

Some people think that more is better! Not in the case of octane. What an engine requires is all that is needed. There is no more energy in a gallon of 93 octane than a gallon of 87...how could there be an increase of mileage? One has to wonder where people come up with these thoughts! As pointed out earlier...octane is more an anti-knock deterrent than anything else. We are not running ultra high compression engines here, so no need to waste money...unless you have an abundance of it and don't mind giving it away!

 

[jreiter]

Incidentally, when I filled up in Flagstaff, AZ, their regular unleaded was an ultra-low octane of 85. I was concerned about this until I learned that lower octanes are required when your automobile is operating at higher altitudes. Less O2 at altitude means less risk of detonation and less need for higher octane. You learn something new everyday.

You are absolutely correct. It's also unfortunately means your motor is making quite a bit less power at higher altitudes than lower altitudes, but at least you can save money by running lower octane.

 

[JB.]

What I'm getting out of all this is that engines are mechanically designed, largely due to compression ratio, for a certain octane and can't significantly utilize a higher amount because of that design, ECM or no ECM. Sound about right?

 

[socal4rnr]

I have one very important question for everyone. I bought my 2010 Limited 2 months ago and have only used 91. i have less than 2,000 miles on it. Sorry I have an M6 BMW so all I know is 91 octane. If I go down to 89 or 87 will this hurt my engine if I've been using 91 since day one on the 4Runner?

 

[Mtn.Rush]

I have one very important question for everyone. I bought my 2010 Limited 2 months ago and have only used 91. i have less than 2,000 miles on it. Sorry I have an M6 BMW so all I know is 91 octane. If I go down to 89 or 87 will this hurt my engine if I've been using 91 since day one on the 4Runner?

You will be fine.

 

[luv2eat]

I have one very important question for everyone. I bought my 2010 Limited 2 months ago and have only used 91. i have less than 2,000 miles on it. Sorry I have an M6 BMW so all I know is 91 octane. If I go down to 89 or 87 will this hurt my engine if I've been using 91 since day one on the 4Runner?

Simply put, no. The 4Runner is good for 87 octane. I have a GL450 that I sometimes feed regular unleaded and it runs fine, but it does "require" 91 or better. All other cars I've owned either required or recommended 91 or better. None of them ran poorly nor damanged the engine when I fed them 87now and then. I believe the ECM will adjust for the different octanes used. Someone correct me if I'm wrong.
I know of a few people who own a MB 500 series AMG and M3/M5 who only put regular unleaded. The gal who owns the AMG has been doing this for 8 years now; no problems whatsoever with her car.
Having said this, I personally would not use 87 octane on a regular bases if the car requires 91 or better if I planned on keeping the car a long time, which I do.

 

[chiefadrian]

87 Octane

Hello all. I am rapidly approaching 16,000 miles and have been the proud owner of my Blizzard Pearl SR5 since March of this year. I have used nothing but 87 and average approximately 17.5-18 city/ 21.5-23.2 hwy spending 70/30 cty/hwy. Every 2-3 tanks, I add Lucas fuel treatment, more so out of habit than anything else. On a side note, thanks to all of you seasoned 4Runner owners that post on this forum. I owned three Jeeps... 2 Cherokees and recently, '05 GC TR... I will most likely never go back. Toyota got it right!
:banana:

 

[SeattleMike]

What I'm getting out of all this is that engines are mechanically designed, largely due to compression ratio, for a certain octane and can't significantly utilize a higher amount because of that design, ECM or no ECM. Sound about right?

You are correct sir. Since most high compression engines are in performance cars, people began to equate higher octane with better performance, and the gasoline station owners are happy to let that misconception continue because they make more money off "premium" and "super". Even those names feed into the misconception; who wants regular gas when you can afford super or maybe even PREMIUM?

The higher octane content is needed for high compression engines. All the rest is just hype and sales and the persistent belief that if something costs more it must be "better". The people that design engines have a thick book of formulas and data to determine what grade of fuel to use and if they recommend 87, it's based on science and not the subjective feelings of a shade tree mechanic. There is a reason even the engines have computers these days. It's no longer as easy as twisting a distributor cap a few degrees and gaining a few horsepower. The computer can adjust for 85 octane at altitude, just as it can adjust for 91 on a hot day, but it was designed for 87.

 

[Fuzzylogic]

Hello all. I am rapidly approaching 16,000 miles and have been the proud owner of my Blizzard Pearl SR5 since March of this year. I have used nothing but 87 and average approximately 17.5-18 city/ 21.5-23.2 hwy spending 70/30 cty/hwy. Every 2-3 tanks, I add Lucas fuel treatment, more so out of habit than anything else. On a side note, thanks to all of you seasoned 4Runner owners that post on this forum. I owned three Jeeps... 2 Cherokees and recently, '05 GC TR... I will most likely never go back. Toyota got it right!
:banana:

There is no reason to add the fuel treatment either. Buy good 87 octane at a station you trust. Happy motoring.

 

[jreiter]

The higher octane content is needed for high compression engines.

And just to expand upon this idea a bit for anyone who's curious, note that supercharged or turbo charged engines are basically the equivalent of *very* high compression engines, which is why they almost always need 91 octane or higher. Many cars which are super or turbocharged from the factory may be able to temporarily run on 87 octane in an emergency (if you have no other gas to choose from), but you usually must be very careful when doing so. Always check your owner's manual first.

Along those same lines, if you were to add a supercharger or turbo to an engine that didn't come with one from the factory (such as adding a supercharger to a 4runner), you'd have to run higher octane even if the engine was originally designed to work with 87 octane. Once again, this is because the supercharger or turbo are effectively increasing the compression in the cylinders by shoving a whole lot more air in there than the pistons would've normally sucked in on their own. That higher compression needs higher octane.

There is a lot more to it, of course, once you start considering timing, intake air cooling, spark plug temps, etc, but you get the basic idea.

 

[jreiter]

There is no reason to add the fuel treatment either. Buy good 87 octane at a station you trust. Happy motoring.

:iagree:

 

[harper7]

The dual vvt-i 1GR-FE in the 5ths senses that a higher octane fuel is used most likely by the knock sensors and vvt-i exhaust sensors and adjust the valve timing to get more power. That's the beauty and PFM of a variable timed engine!I've read alot on these engines as I'm an engine guy,love engines and work in engine shop. Several reviews list different power ratings according to the gas used with variable timing engines. Nobody else has noticed different HP ratings for the 4runners in reviews?

I have a ScangaugeII ScanGaugeII - Trip Computers + Digital Gauges + Scan Tool in my truck and reading it all the time I always have one plugged in my OBDII port.It sits right in front of me on top of the steering wheel in that little nook under the oem gauges.Great investment and gets real time readings from your trucks ECM, have had one for years! I of course played with different rated fuels and yes you do get an increase in HP.The scangauges x-gauge reads real time HP with our trucks but I don't think it would hold up on a real dyno but at least gives something to judge by, rather then peoples internet quantificational fallacies.

With the DT headers and running 93 octane Shell I got it up to 323hp on a nice cool night run on the interstate onramp a couple of weeks ago coming home from work late at night.Usually get 302-305hp on 87 octane on a cool night.The highest I've seen without the headers was 297hp running the higher octane.The question is do you really need the extra horses? Usually I just use 87 reg as it's cheaper,don't really need the extra ponies and I get bad gas mileage as it is with my big ol' heavy mud tires.Higher rated fuels are not going to hurt the engine as it adjust for it with the ECM.I don't think I'd put any purple Avgas in it or anything!!

Description of the 1GR-FE six cylinder engines used in the 4th and 5th Gen 4Runners.....

The 1GR-FE is the 4.0 L version. Bore is 94 mm and stroke is 95 mm. Output is 236 hp (176 kW) at 5200 rpm with 266 lb·ft (361 N·m) of torque at 4000 rpm on 87 octane, and 239 hp (178 kW) at 5200 rpm with 278 lb·ft (377 N·m) at 3700 rpm on 91 octane. This engine features Toyota's VVT-i, variable valve timing system on the intake cam and a compression ratio of 10.0:1. An updated version of this engine features Dual VVT-i, increasing output to 254 hp (189 kW) and 270 lb·ft (366 N·m) on 87 octane and 285 hp (213 kW) and 289 lb·ft (392 N·m) on 91 octane. Inside, the 1GR uses a taper-squish combustion chamber design with matching pistons to improve anti-knocking and engine performance, while also improving intake and fuel efficiency. Toyota adopted a siamese-type intake port, which reduces the surface area of the port walls and prevents fuel from adhering to such walls. This engine has special cast-iron cylinder liners cast into the block, which are a spiny type to improve adhesion between the liner and cylinder block. With these special thin liners it is impossible to bore the block. In the event of cylinder wall damage (scoring, deep protrusions, etc), the entire cylinder block must be replaced. For increased block rigidity, the 1GR also receives a high temperature plastic insulator/protector, which fills the empty space between the outer portion of the cylinders and block material common to open deck engines. For increased cooling efficiency, the 1GR employs water passages between the bores of the engine. There are two such passages for each bank for a total of four. This reduces cylinder hot-spotting and keeps combustion chamber temperatures more uniform.

 

[3rdToyota1st4R]

I wish I would have had that ScanGauge in my Tundra! 381hp+Magnaflows+Volant CAI=one grizzly beast! Of course, who knows what hp was getting to the wheels.

What I do know is that running reg gas in that truck made her run sluggish. Premium ensured a very clean throttle response. Im not an engine guy, not very technically inclined, but I am very in tune to how my vehicles operate.

I dont think anyone will ever agree. I do like harper7's most recent input and description. I think Ill stick with that.

I wonder what kind of conversation we can get started by talking about pickup truck tailgate position. Better gas milage with tailgate down?

Ok, go...

 

[Riser]

The truck is designed for 87 octane. Running higher octane will not hurt, but it won't provide much benefit. On a dyno you probably would see an extra hp or two with high octane gas. But as previously said, is it really worth it? The only time you really need to run higher octane gas is if you change the mappings in your ECM. But again, we're talking about an SUV here, not a sports car.