anyone having any luck

 

I've done the basics to my truck and have had pretty good results, and I have yet to tune.

Intake, cat back exhaust, tonneau.

I get 21-22 highway, and what seems like 18 city.

 

x2 on L7 Sierra,Plus with my I bumped to J.B,A, 8mm plug wires.And every 8K I changed fuel filter,and round every 20K I have the fuel injectors cleaned.And I get The same as L7 Sierra on the gas mileage. I don't a custom tone, But I'm thinking about getting one.

 

the purpose of a tune is to make the engine operate more efficiently. If it's operating at ideal settings its going to get better performance and increased fuel mileage.