87 Octane Gas: Minimum vs. Recommended, & Benefits (if any) of Higher Octane Gas

This has been brought up before in the 3 million other "what octane..." threads. The early years had a line in the owners manual that said something like " for optimum performance use 91 octane" or something like that. I've never found or gotten any answer about why this was changed but imo if Toyota used to recommend higher octane it must have been for a reason.

 

Ran 87 octane for almost three years. Some pinging under certain conditions, but not a huge deal.

Switched to 91 octane six months ago. Pinging disappeared and gained 1 MPG.

 

You got an interesting case. No offense here but I got my first chance to try out ethanol free(they only had 87) in Florida before drove back to N.C. and yeah $.75 more/gal. I was excited because non where I live. I expected it would give me a better mpg, but it didn't. I got the same results as 87 with ethanol. Same distance same interstate(95). That's on my truck and my scanguage. The only different was driving day and night.

 

There's an ECU reflash for your engine assuming it's a 4L. Take it to the dealer and ask for it.

 

I switched to 91 to stop pinging, and prefer how it runs. It feels better. I occasionally will throw in 89 during cold months but generally just roll 91 all the time. The cost difference is like $4 for a full tank, I'm not sweating that.

 

There was a Bulletin from Toyota about it for the FJs. Basically for the dealers to just "tell people 87 is fine"



From what I gather they simply put to use premium because the vehicle was tested and numbers were published using said fuel. No reason the 4L shouldnt run the same around town. Not sure how many, if any, usable ponies 87 would make.

Part of me thinks Toyota thought that it makes a car seem more niche and high performance with that sticker under the gas door.

 

Thanks for the heads-up. I wonder if they would have done the reflash at my 5/10/15k service without telling me? Will ask next time I go in.

 

This has been my exact same experience (but I discovered it after about 3 months). FYI-- I gained nothing going from 91 to 93 (although I'm often forced to use it when the only options are 87/93).

 

If memory serves me the first few years of the 2nd gen required Premium and had a 245 HP rating.

 

You need to understand the definition of octane and cetane and the point of ignition. Then you need to understand what type of engine you have. Running a fuel that the octane is to high for your trucks engine can actually cause problems. Why do you think Ferrari's run 98 octane and your tacoma runs 89. A high performance engine needs a faster explosion in the cylinder. Where your slow moving tacoma doesn't. So regardless of everyone thinking that putting higher octane gas in there tacoma is making run a million times better is actually false. Your just throwing money away. If in fact you want your truck to run better try servicing your fuel system and run the recommended fuel that toyota says to run.

 

Yeah its one of those topics where half of people will tell you octane rating does not matter, others will tell you its miracle.
IMHO, better octane means cleaner fuel, because to achieve higher octane fuel companies have to better distill the fuel.
Also our trucks have enough compression and mapping to make use of higher octane, so if you drive to take advantage of it you will see an advantage.
So in essence if you dont know how to take advantage of higher octane, dont waste your money on it, if you do, you probably know the answer which one is better.

 

Same as my 2014 owners manual. And this makes me think... I can run 87 or higher. Fairly cut and dry.

If I shouldn't be running 93 it seems like the manual would say 87 or higher but not more than 91.

 

correct me if I'm wrong but altitude plays a role in octane requirements too.

 

Same as my 09

 

I know it's Wikipedia, but I seem to recall the latter numbers being published by Toyota when the 2nd Gen first came out and when they spec'd 91. IIRC, it was later spec'd for 87, but the output also dropped a bit.

The 91 gives a torque bump and at a lower RPM as well.

"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"

 

It's possible. My pinging immediately went away and it was bad. I still run the premium though 'cause my fuel mileage is better and I feel like it runs nicer.

 

Octane only changes the temperature of ignition. Higher octane is used when compression is higher to prevent pre-ignition before spark. Higher octane does not contain more energy. More power can be gained in variable timed engines when the computer senses a higher octane rating and allows compression to build slightly higher before spark. Whether the Tacoma does this or not I don't know.

 

My ping was never really that bad. Just on grades and and with a certain amount of pressure on the pedal. But I agree with you- I feel like it just runs a little better. I also notice it on off/on ramps on the interstate.

 

If the engine is VVT it should make a difference in how far it can advance timing... There will be two separate fuel and ignition timing maps to match the valve timing. Might not be much, but there is an advantage to it. I'm intimately more familiar with Honda's VTEC timing and fuel maps (turbo with Uberdata) than I am with Toyota's VVT setup. In conjunction with the knock sensor readings if there is no knock it can keep advancing ignition timing until it reaches its limit point. If there is knock (engine "ping") due to lower octane fuel usage the system will retard ignition timing giving you less than optimal power. Now if Toyota set it all up with 87 octane being the maximum spec, it won't matter at all, but I doubt that they would limit it to that fuel when 91/93 is available most places.

IANAL and I didn't stay at Holiday Inn last night though...

 

+1, in at least 5 places.