Has anyone run their VMS tune on 87 octane?

[piecesparts]

Has anyone run the 91 octane tune on 87 octane fuel? Did the car run alright, or did it have runni ng issues. I am looking at a ECM/TCM tune next month at Vestor and the wife is having issue with the cost of 91 fuel, at every fill. I have upgraded with a Vararam and axle backs from MF, and the tCM tune is really on my list for the next item, will the ECM tune have to be supported by running 91 full-time?

[BigRob]

i believe it will need the 91 octane. i was thinking the same thing because i was running 87 octane forever, and i wanted to run the 91 tune for the first tank of 91 that i got. people recommended that i wait a while to run the 91 tune so the car can adjust to the 91 octane. this led me to believe that it really is necessary. i did some research on putting 87 in a 91 tuned car, and most say that it wont do anything the first time, but not to make a habit of it. i believe that it will retard timing and cause knock, but im no expert. im sure someone can chime in with a better answer for you.

[blackoutgt]

i've heard that with a tune and 91 octane you'll be pulling better MPG which will help offset the price of 91. Tell that to the wifey...that's the only way that I can ever rationalize getting it done.

Props too for keeping the lady happy... you are a wise man.

[GeorgeInNePa]

If the higher octane is $.20 more per gallon and you get 20 gallons each time you fill up, you are spending a huge $4 more per fill up.

:wacko:

Buy 2 less Latte Grandees per week and you're safe.


This reminds me of people who will cross 4 lanes of rush hour traffic to save $.02 per gallon.

I won't move my car from Pump 2 to Pump 4 for $.02 per gallon.


;)

http://img.photobucket.com/albums/v320/GeorgeInNePa/Comedy/pimp_hand01.gif

[-Ray-]

The other thing to discuss is the increased gas mileage that offsets the increase in cost per gallon.
However, given the question, you can run 87 in a 91 tune. There are two maps in the ECM. You don't want to run it hard because you will see lots of KR. When the ECM sees "bad" gas it'll drop it down into the lower map.
Drive it "normally" and you won't have any issues.

[chuckwi11]

If the higher octane is $.20 more per gallon and you get 20 gallons each time you fill up, you are spending a huge $4 more per fill up.

:wacko:

Buy 2 less Latte Grandees per week and you're safe.


This reminds me of people who will cross 4 lanes of rush hour traffic to save $.02 per gallon.

I won't move my car from Pump 2 to Pump 4 for $.02 per gallon.


;)



Thank you! I see these comments all over the forums about the cost of 91/93 octane versus 87. At 20 cents a gallon X 20 gallons X 52 weeks (assuming a tank a week) that only comes to an additional $208 a year. I realize times are tight but you got to really be in a bad way if you can't afford $4 a week. :nud:

Think about that the next time you drive an additional 10 miles to get cheaper gas. Even if the difference is 10 cents from one station to the next the REAL savings is $2.00 - the added fuel spent - your time. It's amusing when people will become so thrifty for such small amounts.

Bottom line... you might need to re-evaluate your life style and investment strategies if this type of stuff breaks the bank. I'd venture to say that we all waste money in other ways that cutting back or eliminating would show a greater return on investment. Like was said cut a latte or consider public transportation!