I have a 89 perf custome tune, can I use 93 octane fuel

 

no, its not what its tuned for.. and if you do listen for detonation

 

YOu are not going to get detonation using a higher octane than the tune calls for. Only if you use lower. Yes, you can use the higher but unless you bump your timing up, it will gain you nothing.

 

Thx for help, just wanted to make sure because I've been filling up with 93 and didn't want to mess up anything, but emailed mike and am going to order a new tune tomorrow to get that lil bump, thx again

 

You can always use a higher octane gas in the truck on a lower octane tune, ( IE 87 tune and 87, 91 or 93 octane fuel is fine ) just do NOT put a higher octane TUNE and lower octane fuel. 93 tune and anything less then 93 fuel is bad idea.

 

I run an 87 tune from 5star. Always got a bad spark knock even after a few tune changes. I was about to give up on the tune and return to stock but I decided instead to try using 89 octane gas. I am so glad I did. I figured it would cure the detonation problem but the truck runs so much better now. Actually performs the way I had expected it should compared to stock. I guess my truck just doesnt like 87 gas.

 

If you get spark knock on an 87 tune using 87, you need to contact the tuner to get the tune adjusted.

 

The more timing the higher the octane required.

 

I did.

 

I'm going to go with the SCT X3 from VMP. What do you guys recommend I get for my 3 custom tunes?

I live in AZ where non-premium gas is 87 octane. Should I just go with 87 octane tunes? Get all premium (91 octane) tunes? Some of each?

I tow maybe twice a year. Road trips 3 - 5 times per year. Truck is mostly used as local transportation (a few miles here, a few miles there). Fuel economy is important, but not as important as performance. I'm still immature enough to punch it from red light to red light to red light and always have to be the fastest off the line.

 

Then get an 87 tow and 93 performance. You don't have to worry about octane levels when switching before the trip but don't forget to run a few tanks of 93 before switching back to performance.

 

If the highest octane available in your area is 91, then get a 91 tune, not a 93 tune.

 

91 is the highest octane available here.

so get: 87 tow, 91 economy, and 91 performance?

 

I would get all 91 octane tunes. If you have half a tank of 87 and want the 91 performance tune to be used you wont be able to use it until you have a full tank of 91. If not you will ping because of timing changes and not enough octane. For the price difference in the two It is not worth the hassle of waiting for that full tank of 91.

 

I would NOT get all 91 octane tunes. Get at least one 87. What if for some reason 87 octane gas is all you can get?