: Regular fuel change ecm program



JML Plakus
03-07-05, 08:56 PM
Has anyone successfully reprogrammed ecm on 96 Northstar to run on regular fuel vs. premium. With fuel prices looking to hit the stratosphere once again, I would be willing to sacrifice a few of the 275 ponies to save 30 to 45 cents a gallon. Searched for reprogrammed chips, but lots of stuff found to up the horsepower, but not to help run on regular. Give me a shout if you are aware of a "fix".

Katshot
03-07-05, 09:39 PM
There's more to it than simply retarding the timing curve through the ECM/PCM. If that was all that mattered, you could go ahead and run the regular now since the knock sensor would back off the timing for you.

eldorado1
03-07-05, 10:23 PM
If that was all that mattered, you could go ahead and run the regular now since the knock sensor would back off the timing for you.

You CAN run regular now. The knock sensor WILL back off timing. Unless the knock sensor or wiring is damaged, you'll be fine. I personally don't like relying on the knock sensor, but lots of people on here run only regular.

BeelzeBob
03-08-05, 12:59 AM
Just run regular. There is no need to reprogram anything. The knock sensor will detect any spark knock and retard and "reprogram" the spark advance automatically. The engine will run fine on regular in most all situations. At worst, you might notice a slight loss of performance and some slight loss of driveability in very hot weather but it is transparent to most. The slight HP loss at peak power operation with regular is almost un-noticeable....but....rating the engine for HP on Premium requires putting "premium" fuel required on the owners information. The later model year Northstars in 1997 were redefined for regular fuel operation with no changes in the engine or engine calibration....

BeelzeBob
03-08-05, 01:01 AM
Funny how some posts start off with rants about how this "$50,000 car is acting.....blah blah blah...." and the other posts are from people that buy these "$50,000 cars..." and cannot afford the cost of premium fuel vs. regular. LOL LOL LOL LOL I don't know which way to turn......LOL just kidding, really.

eldorado1
03-08-05, 01:07 PM
I know! Jeez! If you wanted to save money on gas, you should've bought a Geo Metro. I hear they come with 3 cylinders now. http://cadillacforums.com/forums/images/smilies/coco.gif

caddydaddy
03-08-05, 01:37 PM
I don't even think they make Geo Metros anymore!

But wouldn't running regular, and the decrease in timing and power require more fuel to power the car? So basically, is the initial savings of a few cents for regular is going to catch up with the extra cost of using more fuel? It still takes "X" amount of power to move the car, and if the engine is making less power, it will rev higher or burn more fuel to achieve the same power, correct?

eldorado1
03-08-05, 02:57 PM
Given the same driving styles, I would assume the gas mileage would go down a couple percent...

eldorado1
03-08-05, 03:02 PM
I don't even think they make Geo Metros anymore!


I guess you're right.... they stopped making them in 2000.

http://auto.consumerguide.com/auto/used/reviews/full/index.cfm/id/2165

mmm... 55hp... http://cadillacforums.com/forums/images/smilies/ok.gif

Dooman
03-08-05, 03:21 PM
I was thinking the exact same thing as Bbob, geeze.. An extra $4 a fill is not that bad for Premium Performance, that's what we pay for in the STS..

dkozloski
03-08-05, 07:10 PM
If you want that economy, you're going to have to pay for it.

Ranger
03-08-05, 09:34 PM
But wouldn't running regular, and the decrease in timing and power require more fuel to power the car? So basically, is the initial savings of a few cents for regular is going to catch up with the extra cost of using more fuel? It still takes "X" amount of power to move the car, and if the engine is making less power, it will rev higher or burn more fuel to achieve the same power, correct?
I began running regular about 2-3 years ago on Bbob's advice. I do not drive the car hard at all. Only an ocassional WOT and I have seen absolutly no decrease in MPG.

JML Plakus
03-08-05, 10:27 PM
Hey Mr Pontiac owner. Bought it used for about the price of a new Geo Metro. What's wrong with trying to save a buck. By the way, the difference to premium is around 40 cents per gallon, so it do add up, sunshine.

JML Plakus
03-08-05, 10:29 PM
We'll give it a try. Thanks for the input.

BeelzeBob
03-08-05, 10:46 PM
Hey Mr Pontiac owner. Bought it used for about the price of a new Geo Metro. What's wrong with trying to save a buck. By the way, the difference to premium is around 40 cents per gallon, so it do add up, sunshine.


Yea....I realize that it does add up. I just see so many posts of people that rant about how their "$50K car does this or that" that it seems sort of incongruous to worry about the cost of premium, that's all. LOL

Pjs
03-13-05, 11:34 AM
Maybe I've got the weird car in the bunch. I started using regular when I first bought it and the avg. milage was between 22 and 24 mpg. After a few months I thought that I should probably try premium...after 2 tanks my milage decreased to 19-20 mpg...I've been running regular ever since and haven't had a problem yet.