Hey guys, I have searched around a bit and have found some mpg info when swapping an Lq9 into a 1500 rcsb but most of the info I have found are engines with cams and or power adders.

So I want to know what kind of mileage I should be expecting out of a stock lq9 with a Black Bear tune, 4L60e, 3.73, and 29" tall tire. Last tank I babied it as much as possible and it got 12.5 mpg 95% in town, stop light to stop light driving. A few tanks back it got 17.5 mpg 95% highway.

Do these numbers seem right to you guys? To me they seem a bit low. I was guessing I wouldnt dip below 13 mpg city until at least a cam or converter change..........

 

not great but not too far off..

 

Those numbers are about accurate. I remember seeing around 13 mpg city when my setup was essentially just a stock lq9 (seems like ages ago lol). I did pull down 23.5 mpg from Indianapolis to St. Louis with the cruise set to 70. 3.42 gears at that time. It would get 18 highway with 4.10s.

 

Ok, so sounds like its not too far off to be worth talking to Justin about the tune. I guess it just gets a bit worse than I was expecting over the 5.3. Oh well, I didnt put it in for mpg anyhow........

 

I get 14 in the city and around 19-21 on the highway. I got a 3.42

 

This might be a apples to oranges comparison but my lq9 ecsb truck gets a lot better gas mileage than my 5.3 Yukon did. My lq9 averaged about 16.5 mpg according to the dash combined city and highway. My Yukon was luck to get that on the highway.