Mod question

[vb101]

I know the SCT and Diablo tuner web sites state that "unless otherwise stated the tunes require premium gas...". They seem to imply if not outright state that installing a tune and not using premium gas you will not get any horsepower increase. This may be true but if adding mods like a cold air kit requires a computer reflash, giving it a tune, this would seem to mean that if you mod your car you will no longer be able to use 87 octane gas. I understand that putting in high compression pistons or a hot can would necessitate the use of premium gas but simple bold on mods? I was always under the impression that it was just that the cam and the compression ratio that mainly determined whether or not you would have to use premium gas. It would be nice to do some mods and not have to spend more on gas even if it means not getting quite as much in the way of hp gains. At least there would be some performance improvement. Maybe I'm just dreaming.

 

[Aipaloovik]

When I got my STC, the person I bought it from asked me not only if I wanted to use premium, but what octane the premium gas was in my area. A good tuner should be able to put the proper tune in your car for whatever fuel you wish to use as well as the bolt on mods you have. In fact the guy I bought mine from offered to give the STC multiple tunes, one for premium and one for regular.

I believe the use of premium fuel allows them to advance the timing in the vehicle as it prevents premature combustion. From what I gather, advancing timing does good things to your power curve. Of course I claim complete automotive ignorance and the afore stated information is based off of stuff I read, but didn't necessarily understand, on the internet.

For what it’s worth, I’m quite happy with my tune. I use premium fuel and had my tune specified to the 91 octane available around these parts. I only burn a tank every 2 weeks so the price difference doesn’t really bother me.