Better MPG with better suspension?

[rajingles]

Hey,

So I installed tuft truck variable rate coil springs and some bilstein 4600 on my Rwd QC V6 3.55 gears. It already had a 1.5" rake and it went up to about 3.25". I have a total of 800 lbs of accessories, tools and including my own weight. Strictly on the highway. My mpg has went up from 20-23mpg to 25-28 mpg. mpg is acheived going both 100km/h and 120km/h with a light foot obviously, on rolling hills or flat. I also know that the indicator on the dash is about 1-2mpg off aswell.

Is this due only to aerodynamics of the rake or also the stiffer less bouncing ride?

Wanted to get some spindles for the front but not so much now with the better fuel economy.

Thanks,

Raj

 

[62Blazer]

Really no reason that a lift, or "better" suspension", would increase fuel mileage. In general any suspension lift would at least slightly decrease fuel mileage because the increase height increases the front surface area of the truck and thus increases wind drag. Somebody may want to argue this if you saw a real small change in MPG, but you are stating a 25% increase (5 MPG) which is absolutely huge. There has got to be some other variable going on.
Did you change tires?
How many miles have you put on the truck showing this change in MPG? I can see somebody that normally drives a lot of city routes or stop and go driving which causes lower MPG, and then goes on a long highway trip that offers higher MPG right after the modifications.
Again, not disputing that you saw a change in MPG but there is no way a lift would increase and especially not by 25%.

 

[mtnrider]

No way changing the "rake" made that big of a difference. Either your calculations are off (most likely) or the driving conditions were different.

Trust me, the manufacturers have considered every possible avenue to gain mpg and if it was that simple it would have been done. The rake that came from the factory was the most efficient.

 

[rajingles]

28 mpg is the extreme end mostly been around 25-26 mpg. I have been driving for about a month with the new rear suspension and Im just saw better numbers right after installation. Wasnt looking for it, just noticed it.

I do have alenza plus h/l highway tires.

 

[zrock]

no way that would make a difference and give you better. If anything you should get worse