Today i put 93 octane in my truck because i'm gettin my tuner from Doug tomorrow (hopefully) and i was on E because i thought it would be here today. I took a trip, about 150 miles there and back, tonight and i noticed i got very crappy mileage compared to 87. Has anyone had this problem? Usually on 87 i have at least a half a tank or a little bit less left. Now i have less than a quarter left running 93.

 

i think the higher octan causes it to burn up quicker because it sparks easier...

 

Most vehicles are not meant to run 93, so it burns it faster I believe, but I am probably retarded. Bob can probably answer this for you, he,s pretty good at that:)

 

93 octane burns slower than 87 octane, that's why it is less likely to detonate in a high compression engine. As far as your fuel economy goes, it will generally decrease slightly with higher octane fuel. However, it can increase in an engine like yours if the knock sensor calibration is setup for advance as well as retard. Bottom line: I would be reluctant to make any generalization about fuel economy based on the experience of a single tank of fuel.

 

I thought that you had a 4.0 Justin?

Brenton

 

no B i gots a 3L...so if i'm loosing mileage somewhat, will the tuner make up for that?

 

If it has a program calibrated for the 93 octane fuel, the additional spark advance should boost your fuel economy.

 

I usually get between 17 and 18 if I run mid grade (89 octane here) I have to or else truck pings. I ran 93 Octane a couple weeks ago and got a little over 20.