TTORA Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
116 Posts
Discussion Starter #1
I just want to run something by you guys...

I've been reading up that although the 4.0L Taco engine will fine on 87 octane fuel that you get better performance when using 91 octane.

Now, at first this didn't make any sense to me. I'm of the school of thought that octane makes no difference to a fuels performance, only to it's resistance to detonation (pinging).

Now, what I've been thinking is that the engine's computer is using it's knock sensors to retard the performance of the engine enough to avoid detonation with the lower octane fuel (I'm thinking it runs the fuel:air rich)... and that the higher octane fuel allows the engine to work at full capacity.

Any thoughts/explanations? Am I right out to lunch?

If my theory is somewhat accurate do you suppose higher octaine fuel would give better mileage?
 

·
Registered
Joined
·
133 Posts
I can't answer your whole question but I do know my Taco gets better mpg with the 93 octane.
 

·
Registered
Joined
·
133 Posts
That's a good question. I haven't actually done an in depth comparison, but my rough estimates suggest that the 93 still costs a little more. Personally, from an environmental impact standpoint I feel a bit better burning less fuel and cleaner fuel even if it costs me a little more. I know some will not share that thought, but I can afford it so I do it.
 

·
Registered
Joined
·
422 Posts
I can’t answer your question ether but I can say for sure the 93 makes my truck run smoother. I don’t know if smoother and livelier = more power, but I will stick with the 93.
I don’t get the pining with the 87, but still it seems to not run as nice as the 93.
 

·
Registered
Joined
·
116 Posts
Discussion Starter #7
Cool.

I filled up the other day so that I could measure the fuel mileage on 87. I'll post my results when I run down this tank and a tank of 91 (91 is the best we have around here).
 

·
Registered
Joined
·
2,903 Posts
I did the comparason between premium and regular.

It was about a year ago, so I don't remember the exact numbers.

The final outcome was that burning premium cost more.

Yes, I got slightly better mileage on premium, but it wasn't enough to offset the difference in cost.

As for the performance difference, yes.

The computer uses a knock sensor as one of it's inputs and it allows the motor to be tuned for more power when burning premium.
 

·
Registered
Joined
·
463 Posts

·
Registered
Joined
·
1,022 Posts
I ran 87 octane for the first year of having my truck, because it was alot cheaper. I just switched to 91 octane and have notice some power gain and little better gas mileage. Probably not enough to justify spending the extra 30 cents but thats just me.
 
1 - 11 of 11 Posts
Top