In "computereze" (is that a word?), zero (0) is some "baseline" setting. It could be a true zero advance, but I suspect it is the factory advance setting, which could be 5 degrees BTC or any other setting the engineers think is best for the design fuel octane.

I guess to answer your question, a setting of +1 is probably a 1 degree advance from "where you're at". (At least that's my take on it).

- Jack

 

Timing isn't set at zero. Things like the Edge, for ease of tuning, sets "factory timing" at zero. Timing should only be altered on the Edge when increasing fuel octane. I believe Edge recommends 1.5+ on the Edge running 93 octane.

Regardless, like I said before, we can sit here all day and argue about this and that. The answer to the initial question is yeah 93 octane tune will give better mileage than 87 octane. Not to mention more power. I don't care what specifics you want to get into it but that's the case. If you want to argue about it, spend some money and do the testing yourself. Get a tuner with a 93 octane tune and a 87 octane tune. Do some real world testing, see which one gets more mileage, and which one is more for the money. Throw it up on the dyno, see which one puts down more power. I already know the answer.

 

I talked to Jim Paschall at www.Swtuning.com over the weekend at our local Corvette show. I asked him about a tune for my truck. I asked him about increasing mpg. He said to be honest it would not do much for highway mileage, but I would see an improvement in overall drive ability and city mileage.

 

Thumper my friend, I am not fighting you here. I agree that a 93 octane tune running 93 octane gas gives more power and better mpg!

That is NOT the issue. What is the issue, is, do we save money in the long run with this high octane setup?

If, your extra miles driven on a tankfull of high test gas translates to a lower cost per mile every time you fill up, then, the 93 octane tune is the way to go. We should really be comparing cents per mile figures here, not miles per gallon.

On that metric, I'm not convinced there is a clear cut answer!

- Jack

 

Cost per mile will vary from day to day with our ever increasing gas prices, vary depending on which market you're in, and will also vary from one gas station to the next.

 

well just to make it easy.
93 is $.20 more were i am (Houston, Texas)

on a 25 gallon fill up that = $5.00 more. A once a week fillup with 93 will cost you $260 a year more.

it is probably a wash or so little that it dosent matter. ( you can take this 2 ways. get the 93 and enjoy or get the 87 and feel like you are giving a little)

when a fill up is $100 or $105 does it really matter?

 

Not as much there but I've seen 93 go for as much as $.40 more than 87 per gallon. And filling up more than once a week at 27 gallons that adds up to me where I think I'm going to have my truck re-tuned for 87 perf instead of the 93. Hard for me to justify spending almost another $600 a year for 5-10hp (probably not even noticeable) and little to no gain in fuel economy.

 

40 cents different? Geez, its only 20-21 cents different in FL.

When 87 was $1.00 per gallon and 93 was $1.20 a gallon, 93 was 20% more expensive than 97.

Now that 87 is $4.00 and 93 is $4.20, 93 is only 5% more expensive than 87.

So in order to break even with 93, you would need to get approx .7 to .8 miles per gallon better than 87 assuming 15 mpg as a generic baseline. If you could get 1 mpg better with 93, then it would clearly be more cost effective.

If/when gas goes to $5.00 per gallon it will take even less of an increase to break even with 93.

Interested to see some real world numbers befor buying a tuner. I have been eyeballing the SCT3 and figure I would go with Justins tunes since his shop is in the local area. One thing that has me concerned is the recent change here in central florida to a 10% ethenol blend. Its at all of the pumps and in all octage grades. Not sure if the current catalogue of tunes will be effecitve with this crappy gas they are shoving down our throats. Ive seen about a 1 mpg drop since the switch to e10.

 

My experience w/ edge and 87 vs 93 tune....

93 Octane cost an avg 6-7 bucks more here and I get....

better MPG... around .7-1.0 better

Power and Driveability... you can definitely feel a power difference and truck seems to run more effortlessly in both highway and city settings

conclusion- 93 octane in MY experience is worth the extra 6-7 bucks IMOH

 

I changed from my 93 perf to 87 perf tune about $1.25 a gallon ago. Sure I miss the additional horsepower but $85 - $90 a week is enough already. It is all about $/mile these days.

I am glad I had my tunes updated for E10. If you live in an E10 state you should do the same. I noticed the power and mileage drop when E10 became the law of the land around here. It is only a matter of time before E10 will be everywhere.

 

Here in CA, the best that we can get is 91 Octane, and I just paid $4.85 a gallon.

 

Well, I live in C. FL too and I remembered you saying this so I checked a gas station on the way home today. Regular was $3.99 & Premium was $4.35. So a good difference.

 

Well, I live in C. FL too and I remembered you saying this so I checked a gas station on the way home today. Regular was $3.99 & Premium was $4.35. So a good difference.

 

WHAT !? Where are you buying your gas !? All of the BP's around here are only a $.20 increase to 93 octane from 87 octane ...

 

You must either be looking at gas prices near the airport or near Disney or looking at the diesel price, because all 4 of the gas stations within a mile of my house have a $.20 to $.21 split between 87 and 93. Dont get me wrong occasionally I see a station asking some ridiculous price for 93, but that is the rare exception. My motocycle requires 93 so I keep up with the prices.

I know that the difference can be more in other states, but Im only concerned about where I do 99% of my driving.