Nbs Silverado 4wd Level Kit Issues (drag)

swaco · February 11, 2009

Got a ReadyLift 2.25" leveling kit installed on my 07 NBS Silverado 1500 4*4 about 2 weeks ago.

I first thought its the new wheels with the Nitto TGs, but I switched back to my original wheels/tires to check:

My overall mileage went down about 2-3mpg and I get an overall feel of more 'rolling resistance' in 2WD mode.

4WD is even worse. Going stright seems normal, but a medium turn in idle brings the truck to a halt ! It never did that before the levelling

Anybody got some clues ?

According to all I read I could find, just levelling should keep the front end inside all mechanical specs.

Ideas much appreciated !

Thanks.

2000DV4.8 · February 11, 2009

Did you get the truck aligned after the install?

swaco · February 11, 2009

Did you get the truck aligned after the install?

Yes, all professionally done incl. alignment etc.

I also don't hear anything unusual like mechanical noises that something would lock up or so ...

Silverado4x4 · February 11, 2009

I noticed the same thing when I had my leveling kit on, I lost about 2-3 mpg's due to the front up higher now and more air is getting up under the truck and making drag, my hood would sometimes fludder at about 65 mph. I removed it cause the hood fluddering got on my nervous. You dont want to put it 4x4 on dry pavement and try to turn as it will bind up the drivetrain and thats why your truck is coming to a halt.

swaco · February 11, 2009

I noticed the same thing when I had my leveling kit on, I lost about 2-3 mpg's due to the front up higher now and more air is getting up under the truck and making drag, my hood would sometimes fludder at about 65 mph. I removed it cause the hood fluddering got on my nervous. You dont want to put it 4x4 on dry pavement and try to turn as it will bind up the drivetrain and thats why your truck is coming to a halt.

To me it feels like the same drag at low speed as well, but maybe I'm over sensitive now.

The 4*4 engagement on pavement was just a short, carefull test over 10 feet distance I also did before once or twice. Don't remember it as generating that much resistance before the level-lift.

You really lost 2-3 MPGs just lifting the front by 2" ?

If all is mechanically correct with my rig, then all drag is coming from the additional air swirl under the body ? Can hardly belive that and it would mean the Nitto TGs didn't make any real difference over the std Dueller A/Ts either ...

But hey, I'm new to trucks and didn't really study airodynamics.

BuckFeverZ · February 11, 2009

I just got my RC leveling kit put on about 10 days ago so its really too early to tell what, if anything happened to my MPG's. I have used 4wd since then and didn't notice any of what you're saying

J-man67 · February 11, 2009

Got a ReadyLift 2.25" leveling kit installed on my 07 NBS Silverado 1500 4*4 about 2 weeks ago.
I first thought its the new wheels with the Nitto TGs, but I switched back to my original wheels/tires to check:

My overall mileage went down about 2-3mpg and I get an overall feel of more 'rolling resistance' in 2WD mode.

4WD is even worse. Going stright seems normal, but a medium turn in idle brings the truck to a halt ! It never did that before the levelling

Anybody got some clues ?

According to all I read I could find, just levelling should keep the front end inside all mechanical specs.

Ideas much appreciated !

Thanks.

That'll happen with lift. You drive a giant, heavy brick. It achieves its MPG with the front end and truck being lower, making it more aero-dynamic. You take that away and you are going to change the streamline of said brick. The halting in 4wd sounds like you are binding the driveline up. Are you turning on dry pavement while in 4wd? Thats a BIG no-no.

silverbullet2005 · February 11, 2009

I now get about 14-15 mpg city and 17-19 highway with my 6" BDS lift and the 35's, I also have the Gibson exhaust and a Fram airhog air filter if that makes a difference. I drive a big truck so MPG doesn't mean much to me anymore if it ever did anyways, if it mattered much to me I would have bought a chevy aveo!!!

swaco · February 12, 2009

I now get about 14-15 mpg city and 17-19 highway with my 6" BDS lift and the 35's, I also have the Gibson exhaust and a Fram airhog air filter if that makes a difference. I drive a big truck so MPG doesn't mean much to me anymore if it ever did anyways, if it mattered much to me I would have bought a chevy aveo!!!

@SilverBullet:

I don't really bitch about the mpg I'm getting but use it as an indicator that something might be wrong machnically ...

Used to get close to 17mpg in my regular driving, mixed hwy and city. Since the leveling and 285 NittoTGs it was down to 14mpg and stayed at 14.5mpg after putting the original 265 DuellerA/T wheels/tires back on.

So in my simple perception the level-lift sets me back 2.5mpg, the tires 0.5mpg ...

I'd expect the opposite numbers, rough tires having more of an impact than the 2.25" front lift.

But maybe it's not that simple...