@Tune+ Fuel Quality Questions

[Autonomous]

In several threads I've seen your customers remark that their fuel was of good or bad quality which affected your tune parameters. I was wondering if you or your customers kept tabs on which brand or station produced those good and bad fuel samples.

A lot of folks say gas is gas, which is mostly true as there are not that many refineries. They miss the part about the quality/quantity of additives that differentiates Top Tier from random independent stations.

I'm not tuned yet due to warranty, but I'd still like to run quality gasoline while I count the months until I can join the ranks.

 

[Hijinx]

Bottom line is that fuel quality varies. Test your local stations with octane and ethanol testers to know who's best and who's worst. Anything otherwise is speculation. There's no ifs ands or buts about that.

 

[Mr.Fister]

isn't that why you're supposed to drive around until the octane adjust ratio to -1.0 before you do your pulls? I figured it'd give as consistent of a baseline to work with. Mine starts at -.75. In my head, once it gets to -1.0 then the car should be at the level the tune was made for. I'd love to be further educated on the topic though.

 

[Hijinx]

isn't that why you're supposed to drive around until the octane adjust ratio to -1.0 before you do your pulls? I figured it'd give as consistent of a baseline to work with. Mine starts at -.75. In my head, once it gets to -1.0 then the car should be at the level the tune was made for. I'd love to be further educated on the topic though.

OAR can change. It's possible to always have -1 during light load situations, and when you go WOT, it rises slightly. Not necessarily bad, since the ECU is doing what it should according to the tune and what's in your tank because...fuel quality varies.

But, on the whole, yes. When you get a new tune, ride around to get it to -1. Applying light load for short periods will get it there faster.

 

[dyn085]

OAR and the strategy used behind it is dependent on your tuner. If you're seeing -1 on OAR then you're not getting everything available out of your fuel. Realistically though, most tuners prefer you to be there simply so they can leave some additional headroom for safety.

You can take almost any tune to -1 with creative throttle use, but how it reacts at WOT can be another story. Check your fuels that are local and convenient to you, any differences should be relatively noticeable if you keep the tune the same. Don't necessarily worry about specific recommendations though, outside of people recommending a top-tier brand, because there can still be variances between stations within the same brand at different locations.

 

[Sourskittle]

Fresh gas is the best gas to me... Where is the freshest gas? The place that sells the most gas ? The place that has the cheapest gas. But that's just me. E85 is more of an issue with fuel quality than most 91-93oct normal fuel.

Alex has said its normal for the car to add and subtract timing as it goes. Unless you have a cobb OTS tune that is so insanely conservative its almost impossible to see knock, then chances are, even if a good tune, your going to get -1.00~ at SOME POINT. That point should not be every time you drive the car. Or every time you go WOT in 4th gear. But AT SOME POINT. And its not the end of the world. Its just the car doing what its supposed to.

Also... While some think it doesn't exist, false-knock from the driveline or engine mounts IS REAL.

 

[dyn085]

Fresh gas is the best gas to me... Where is the freshest gas? The place that sells the most gas ? The place that has the cheapest gas. But that's just me. E85 is more of an issue with fuel quality than most 91-93oct normal fuel.

Alex has said its normal for the car to add and subtract timing as it goes. Unless you have a cobb OTS tune that is so insanely conservative its almost impossible to see knock, then chances are, even if a good tune, your going to get -1.00~ at SOME POINT. That point should not be every time you drive the car. Or every time you go WOT in 4th gear. But AT SOME POINT. And its not the end of the world. Its just the car doing what its supposed to.

Also... While some think it doesn't exist, false-knock from the driveline or engine mounts IS REAL.

Kinda weird to add to a fuel quality thread but yes, I think most people are aware that false-knock can exist and that there are ways to troubleshoot its possible existence. If not, they should be.