My fuel mileage

**2000liftdsuburban** · 10-06-2009, 11:04 AM

ok so i have a 00 suburban, its lifted 6 inches with 35's and 373 gears im going through gas like mad!
i drive the speed limit and i also have a cold air intake and exhaust(minus the headers)

can someone please! explain to me WHY im going through so much gasoline

**vncj96** · 10-06-2009, 11:13 AM

35's!! Have you had the computer upgraded so that it knows thats what is running now, instead of the factory, 265s. Try and keep the RPMs under 2000 when accelerating

**06SCSilverado** · 10-06-2009, 11:19 AM

pcmforless.com will help you they do great work

**2000liftdsuburban** · 10-06-2009, 11:24 AM

Originally Posted by vncj96

35's!! Have you had the computer upgraded so that it knows thats what is running now, instead of the factory, 265s. Try and keep the RPMs under 2000 when accelerating

im pretty sure it has been recalibrated... my rpms are really never go over 2000 when im driving unless im speeding lol... but i hardly do that anymore.

**vncj96** · 10-06-2009, 11:32 AM

I am guessing you didnt put the lift on you bought it this way? I would bet it was never redone, you can pick up a hypertech programmer for 200 or go and get a cutom tune from pcmforless, blackbearperformance or from wheatley, the two latter tuners are on this sight. i would get a custom tune, especially with that lift.

**dsfloyd** · 10-06-2009, 03:08 PM

One could be the speedo is off the other could be a little in the gearing. if the 3.73's are stock they will be working pretty hard to get the truck moving. shouldn't be as bad on the freeway as the rpms will be low. 4.10 can still be a little underpowered but I found it to maintain my mileage on the freeway. 4.56 will move the truck easily but the Rpms will be increased on the highway dropping highway mileage a little.

Oh yeah what are your driving habits (city, highway etc), and did you just get the truck or is a recent drop in mpg. What is your current mileage? These arent much in the way of gas sippers to begin with.

**2000liftdsuburban** · 10-08-2009, 02:18 PM

Originally Posted by dsfloyd

One could be the speedo is off the other could be a little in the gearing. if the 3.73's are stock they will be working pretty hard to get the truck moving. shouldn't be as bad on the freeway as the rpms will be low. 4.10 can still be a little underpowered but I found it to maintain my mileage on the freeway. 4.56 will move the truck easily but the Rpms will be increased on the highway dropping highway mileage a little.

Oh yeah what are your driving habits (city, highway etc), and did you just get the truck or is a recent drop in mpg. What is your current mileage? These arent much in the way of gas sippers to begin with.

my driving habbits are most likely highway all the time i drive to and from work/school every day i do minimal city driving... i had the truck for a lil while, the lift was done when i got it, and im just noticing a drop in mpg. the geatrs are not stock however, and when i drive the rpms are usually 2 or under. so idk if that should help, the truck also has a fresh tuneup (plugs/wires) and im using the plugs called for the truck as well.

**lsutoms** · 10-08-2009, 06:07 PM

what size motor does this have in it? i have an 06 silverado v6 with 6" suspension 3" body and 35's and it killed the gas. i averaged about 5 or 6 mpg if i was driving city aggressive. i had 4:10 gears put in it and it would pull just about anything (6000 lbs was most ever tried) with ease but it burned like crazy on the highway

**tbplus10** · 10-08-2009, 06:30 PM

Try changing the gearing to something friendlier to those tires.
Your trans probably doesnt like the tires either.
2k RPMS is low for highway speeds, you should be around 2250 to 2500, the engines working too hard to maintain speed and this burns more fuel.