4.8 spun a rod bearing so time for a new engine. Im wanting to go with a 6.0 or at the very least a 5.3, but Im still looking to get halfway decent fuel economy. Truck is a regular cab 2 wheel drive. It already has a built 4l60e, longtube headers and a decent tune. Ill keep the 4l60 trans for sure. By swapping to a 6.0 lq4 or lq9 will I really see a detrimental decrease in fuel economy. I drive mostly highway and dont flog on it except for when I go to the track. Right now its averaging about 17-18 on the highway. I was wanting to do a 6.0 with a mild cam(texas speed 224) and I also have a tbss intake sitting in the garage at the house. Ive searched a lot and found inconclusive evidence. Just want some decent opinions from those who have done it.

 

Mileage should be really close as long as you control your right foot. Do it.

 

Big motor light trucks loafing along. We did a 6.0 swap on my dads 01 RCSB 4x4 when it had a couple thousand miles on it 13 years ago still have the truck runs waaaay better than doggy *** 5.3 and gas mileage actually got a touch better because it's not laboring to move the truck

 

[QUOTE=01WS6/tamu;5219030]Big motor light trucks loafing along. We did a 6.0 swap on my dads 01 RCSB 4x4 when it had a couple thousand miles on it 13 years ago still have the truck runs waaaay better than doggy *** 5.3 and gas mileage actually got a touch better because it's not laboring to move the truck[/QUOTE

Lots of people report the same results when doing a 6.0 swap, it's all over the forums. Try a search.

 

I have done a lot of searching and its almost split 50/50. Seems like half say that its not a detrimental loss and half say its a gas guzzler. I kinda figured it wouldnt be that bad with my lighter 4l60e, 3.42 gears, 30 inch tire, and 2 wheel drive. Especially being a single cab

 

I have a Lq4 bottom end, 243 heads, ls2 cam, long tubes, and cheap intake.

Mileage is about the same as my stock 4.8

Seems a little better around town and a little worse highway

 

Fuel mileage will be affected more by gear, converter size and cam size. My lq4 with a comp 265 has seen 17 plus highway driving. And that's a extended cab with 20 inch rims.

 

My 5.3 got 22 highway, the 6.0 gets 19 highway

 

Right foots biggest factor.

 

This^ and mods.