I have a 2WD/5.3L/ 20 inch tires/ ext cab that was purchased over a week ago. Gone through two tanks of mainly mixed city and highway driving and getting about 12 mpg. I have heard some say that after a couple thousand miles and the first oil change that gas mileage should increase. Others say the change is minimal. I sure hope it improves!

I took it out on the highway the 2nd day I had the truck and was getting about 20 mpg so I am happy with that, but if it ain't on the highway she is a hog! I have a pretty light foot too.

Just curious if anyone else has experience with new silverados getting better as time goes.

 

Nice Ride! I have seen alot of those on the road lately, I really like the new look, they keep looking BIGGER every year.

I am not sure on the mileage thing, I never noticed on mine when I bought it new. Its always been a hog on city MPG, I have the 6.0 though. I have a Tahoe with the 5.3, it can be a hog in the city too.

 

Yeah they do tend to gtet better fuel economy when they reach about 6-8000 miles or so. With a Duramax, the break in period is about 100,000!

 

Interesting, never knew, Thanks!

 

My 08' tahoe got better after about 10K miles give or take,I run mobile one syn oil and avg 14.5 mpg city and 20 hwy.My duramax was about 15K miles before I noticed milage change.Its 14 city and 20ish hwy up from 12 city 18 hwy.

 

Thanks, It's nice to know that. Our other silverado is a 2002 5.3 which my wife bought long before we met, but it gets great mileage today. With mixed city/hwy we get about about 420 per tank.

 

This thread is exactly what I was looking for. I have a 1997 Tahoe 2dr 4wd, slight lift on it and 285/75R16 tires.
For me it is impossible to break through the 14mpg..... that's almost as bad as with the old 5.7 mill in it...
Ohh I forgot, I updated the drivetrain to a 2007 5.3 LMG with a 4L60E both new. I drove it about 1700mls since the swap and it still drinks a lot.....

Harald

 

I have a 2009 Silverado Ext cab (5.3L AFM, 2WD). I'm on my second tank and I'm getting 15 around town and 21 on the highway.

I drive like a grandma though. Strickly 55. I'm thinking I'm going to have to quit listening to the AFM flutter because it's killing my back to try to drive slowly enough to get that mileage thing. I do love my fuel mileage when it's high, but I may be taking it to an extreme.