fuel grade in FJ62

[Herbert]

I'm sure this question was answered many times, but I can't seem to find anything in the forum.
What fuel grade is recommended for the FJ62? Is 87 octane enough or is higher grade fuel better?

Thanks
Herbert

 

[billmc]

The owner's manual calls for 87 or better, but many of us get an annoying low-grade ping if they use 87.

Bill

 

[import silvia]

I use 87 with no problems. I would look into my fuel system if I did have some pinging.

 

[Cabrito]

Makes no difference in FJ62

I started out always using premium because I go to Lake Tahoe a lot and thought it would help in the mountains. Previous owner told me he only used 87 because it's all about compression ratios? Some cars need it - my Cruiser does not.
After a few years I switched to 87 all the time and have found no difference other than it's cheaper. I do run a tank of Chevron premium once in a while thinking it's good for my fuel injectors. (is this a myth?)

**

 

[baldredhead]

i use 87, have taken it to tahoe with no problems

I I do run a tank of Chevron premium once in a while thinking it's good for my fuel injectors. (is this a myth?)

**

yes and no

octane rating does nothing to clean your engine. it is most directly correlated to a measure of detonation resistance. the higher the number, the more resistant to detonation.

if you want your fuel system to stay clean, rotate fuel suppliers periodically or just don't use the same one all the time. the "detergents" are about the only difference between brands, with chevron, shell, arco etc etc using different chemicals to acheive the same result. constant use of a single brand will result in those detergents leaving a deposit of their own, think of soap scum on your shower walls. by rotating detergents, one brand cleans the deposits of the previous one

 

[todd a r]

I throw in a bottle of Gunk fuel system cleaner (white bottle) when it starts pinging. It's worked great so far and I run regular 100% of the time. Just follow the instructions. Near empty tank + two bottles inital application + fill. Then one bottle every so often. Under $2 a bottle. I have not tried seafoam yet. I hear it's the berries but it's also $5+ a can too. YMMV

 

[tclndcrz]

i use 87 most the time and add 91 every now and then just for good measure. i always notice a large power increase when i add 91 though

 

[import silvia]

91 octane contains no more chemical energy than 87 octane per gallon. The only performance increase you might fell would be due to the reduced mass of your wallet.

The octane rating indicates that the fule being measured resists combustion from compression just as a mixture of that percent octane and the remaing percent heptane. For example 87 octane behaves as if it were 87% octane and 13% heptane, while 91 is like 91% octane to 9% heptane.

This is ONLY a measure of resistance to knock. The rating has nothing to do with the energy in the fuel. The engine in our trucks should never need anything more than 87 octane as we have low compression low revving motors. If your engine is knocking or pinging you need to troubleshoot your fuel system, you are leaning out to a very dangerous level.

For the record your engine should be less likely to knock at high elevation that at sea level. The reduced available oxygen means your fuel mixture is more rich not less.

 

[euclid]

If the timing is set right 87 should be fine. If it pings on 87 the timing is probably advanced a little too much.

Our truck were made to run in the worst of conditions. Even with high miles they should run on really crappy gas just fine.

 

[billmc]

Anyway, Herbert, it will likely be just fine with 87, but if you do find you have some pinging under light load with 87 or 89 octane, before you spend a lot of time and money trying to eradicate it, do a "ping" search on the 3FE list archives. It's been discussed many times.

Bill

 

[tclndcrz]

The only performance increase you might fell would be due to the reduced mass of your wallet.

ive been driving this cruiser for four years now and i have been able to notice a sizable performance increase using a higher octane gasoline. it is not the reduced size of my wallet. maybe it is because i have fuel injection. i do not know the facts but i know the feel of my cruiser and i know when it has more performace.

 

[zmontgomery]

My 2F runs just dandy on 85.5 (montana gas), no pinging etc. My dad used to have a 40 with the F in it, and one time while in mexico he ran out of gas in the middle of the desert, and ended up using coleman camp stove gas to make it the last 20 or so miles. He adjusted the timing, and was able to drive about 30MPH the whole way with only a "slight pinging" as he put it. If your truck is having trouble with 87, I would definately look into getting the fuel system flushed, injectors cleaned, etc.

 

[cpip]

This is ONLY a measure of resistance to knock. The rating has nothing to do with the energy in the fuel. The engine in our trucks should never need anything more than 87 octane as we have low compression low revving motors. If your engine is knocking or pinging you need to troubleshoot your fuel system, you are leaning out to a very dangerous level.

I work in a refinery and it's pretty interesting how octane is measured. There are acutally little engines that run on the fuel to be tested. These engines have an adjustable compression ratio, and you increase the compression until the sensors on the engine begin to detect knock. You then compare it to a fuel of known octane and that's your octane.

 

[billmc]

My 2F runs just dandy on 85.5 (montana gas), no pinging etc. My dad used to have a 40 with the F in it, and one time while in mexico he ran out of gas in the middle of the desert, and ended up using coleman camp stove gas to make it the last 20 or so miles. He adjusted the timing, and was able to drive about 30MPH the whole way with only a "slight pinging" as he put it. If your truck is having trouble with 87, I would definately look into getting the fuel system flushed, injectors cleaned, etc.

Of course, the behavior of a carbed 60/40, has no bearing on an EFI 62.

 

[calphi27]

I have been running 85 in my 62 for four years now with no problems. I am at 5000 feet though.

 

[LongIsland60]

I work in a refinery and it's pretty interesting how octane is measured. There are acutally little engines that run on the fuel to be tested. These engines have an adjustable compression ratio, and you increase the compression until the sensors on the engine begin to detect knock. You then compare it to a fuel of known octane and that's your octane.

That's pretty wild - experimental analysis rather than chemical analysis. Never would have guessed that.