I have a 87 octane tune on my nnbs 5.3 silverado, my cousin is going get his truck tuned by the same guy i got my tune done by, i was trying to figure out if its really worth it to switch from 87 to any of the above octanes? I filled up with 93 octane last night and for only 10 more dollars more a fill up really isn't ganna make or brake me. So my question is should i stay at an 87 octane tune or move up to a 89 or maybe a 93 octane?

 

Thats all up to you.. the power difference is not all that much on a stock N/A setup..

Ive run 87 and 93 on long trips and the gas mileage was the same for me.

 

I have another question i had my turner turn off the v4 mode, if i turn it back on will i notice and mpg difference?

 

Did you notice a difference before? It's not going to be much different with a tune. Road elevation and wind play a huge role in whether you can hold V4 mode for an appreciable amount of time.

 

With your setup, i seriously doubt it would even activate goin down hill..

 

I noticed a gain when I disabled v4. But I also redid the fueling map at the same time

 

lol yeah your right i dont think I remember it activating that often maybe for a few seconds.

i never had the v4 activated with my current set up
.

 

do the 93 with 4 off. My 5.3l got better gas mileage with it off and adding 93 I got better mileage with and with out the tune. the mileage made up for the difference in price. I did a lot of testing on it.

 

sounds like a good idea I'm thinking when his is getting tuned ill bring mine to so he can do the 93 octane tune