Maybe a little longer, but, you KNOW it's gonna happen!

- Jack

OHHHH i cant wait.

It went down..... Its only gone up here.

Just to revive this issue! All the stations here are pumping gas with 10% ethanol now. Does this affect our tunes? I have heard that ethanol has a higher octane rating than pure gas. Should the timing be advanced or rewritten into the code?

Ethanol DOES have a higher resistance to pre-ignition, which is what octane ratings are all about, but if the pump says 87 octane, that's its minimum antiknock rating. It COULD be higher, but it won't be less. And, I suppose you could try advancing the timing in small increments (i.e., 0.25) and see what happens.

However, I'm fairly certain the antiknock properties of gasoline are improved through the use of additives in the refining process that contribute to an increase in cost. I don't really see a refiner using those costly additives in the same way if the antiknock properties are improved by adding ethanol. So, I'd guess that the mere fact that gas is E10 has not improved its octane rating.

However, different brands CAN have slightly different octane ratings as long as they meet the minimum shown on the pump. You can experiment to find a brand that will let you advance the timing some. The trouble is, our trucks have anti-knock sensors built in to the system that will actually retard the timing if detonation is detected. So, advancing timing may actually be non-productive.

I know I tried advancing mine once, by 0.25, back when I had an Edge before it was converted to a Gryphon. I immediately noticed an uneven idle. I put the timing right back to "0".

- Jack

The only two or three of the stations serve ethanol as a side dish but I'm still paying $2.57 for regular 87. :disbelief: Suprisingly one of the stations with the 10% ethanol seems to make my $20 last longer than the regular from other stations, and it's not because of the price/volume difference.
I wouldn't change the timing too much but I did get better results on the canned tunes by moving it up to .25 then to .5 degrees. I probably could have gone further but I decided not to.
Jack, my truck is almost the opposite of yours. Before I got my programmer, my truck had a slightly uneven idle. The tunes and advanced idle cleared it up. Ha, that just seems strange to me. :hehe:

Just shows how different trucks are like different people. No two will ever be exactly alike. But, I agree, it's kinda weird how they could be "opposite". I should probably try bumping the timing again now that I have custom tunes. Possibly, I'd get different, and better results. :shrug:

- Jack

I have played with the timing a bit to see if there is a benefit. At +.25 it seemed peppier but less torque. Also had an increase in MPG (this was when I was still running the AC constantly). Tried +.50 but that almost seemed to erase any benefit. I am now running it at the 87 custom performance +0without the AC mostly and mileage is about the same as +.25 with the AC on. I like the way the truck feels at +0 better than with advanced timing. It just seems to pull harder. I'm not a racer, just normal mixed city/highway with light hauling and towing. I will try it again at +.25 now with the cooler weather and see if it makes a difference.

Also my idle seemed to smooth out at +.25, now at +0 it is slightly rough at times.

Thanks for the input, I think ethanol may be here for a while and this may help sort out if we can tweek things to better advantage.

Haha, I bet it can drive Bill a little crazy because he can never be 100% sure how a truck will react.

^That is very similar to what was going on with my truck. Haha, you'd think that since they are machines off of an assembly line that they would all be the same. Sure is strange. :face-lol: But I guess it's those quirks that keeps Bill in business.

Nope, two different machines off an assembly line will never perform the same, even if they are the same model, production run, etc.

I used to see this in aircraft. Each one had its distinct personality. The little tiny differences in tolerances and other production differences are enough to make fairly big changes in performance. I guess that's why a race car is "hand-tuned", from nose to tail.

- Jack

Haha, but back to topic there are some automotive items that I do like to be quirky--gas pumps. I remember one in New Braunfels a long time ago that would keep gas dripping even after the handle was let go. I guess it siphoned or something, but they've probably fixed it by now. :notallthere::hehe: I found one over where I'm at but it doesn't drip fast enough to be worth sitting there. :rofl:...seems like thats is the only time you get your money's worth. lol