Mileage gone for a CR@P !!

[RedRamer]

After 8 trips I can say for sure mileage dropped by about 3 mpg.

It went south after I put on a topper last Fall.

I can't be the weight. last year I did a trip with 1,500lb of steel in the box, no topper, and still got 17. 8 mpg towing 7k lb trailer.

Last 4 trips are 14. 5 - 15 mpg and very last trip was 16. 5 mpg but had to keep it at 90kph (55 MPH). Ususally run 100-110 kpm (60-65 MPH)

Toppers do this?

thanks

 

[Shovelhead]

Yes the topper changes the aerodynamics of the truck.

These might be a solution Airtab Vortex Generators

 

[RedRamer]

Thanks. Those seem to make sense.

I'm going to drop the topper and try it without to make sure that's the cause...

 

[hdtrukn]

Lost Mileage

Think back, did your mileage drop after you put on the LTX A/T's

I bet it did, mine dropped about 2. 5mpg.

And yes I have compensated for the difference in tire size.

I went from 215/85/16 to 235/85/16 almost an 1 1/4" taller.

Rolling resistance is the killer.

Michelin says 1. 5 to 3mpg drop from M/S tires

Just my though

 

[RedRamer]

SWorrall

Same tires... . Had them for 2 years now.

Are you sure about lost mileage?

I have 80 lbs rear and 60 fronts when towing. I also keep 40 in the railer tires, and they don't seem to have much of a sag in them. I know with low pressure, esp on the trailer, it's a drag!!!

goober

 

[Pit Bull]

Originally posted by goober

Thanks. Those seem to make sense.

I'm going to drop the topper and try it without to make sure that's the cause...

Goober I have noticed mine changing by 1-2 mpg just by the direction the wind is blowing. I'm sure it's your topper, but let us know what you find out.

 

[Ron Bissett]

Wind mpg loss ?

Could be loss due to air dam effect of toper , DC tested in wind tunnel and report vent gate to loose mpg to loss of bubble effect. I don't think DC had a trailer or fifth wheel on truck when testing was done. Some people say that air foils (wing thing) do no good but if a camper shell by its shape will cause loss then wings should add to mpg. Small deflector on top with shell could be the answer . I have a home made self supporting wing carry over from former truck but haven't mounted it yet and see if mpg is less or more . We need more input on this subject . Ron Bissett in LOUISVILLE KY:-{} Oo.

 

[RedRamer]

Trailer in for repairs. Putting in a box tank also.

When I get it all together I will try pulling with and without topper to know for sure what the deal is here.

Thanks - goober

 

[keimmmo]

A good topper will INCREASE your MPG compared to running without and with the tailgate up. A topper that cuts the air like a brick will hurt you. Anything that catches air will also have increased drag in cross winds.



Another overlooked economy robbing culpert can be a bug deflector or a rear spoiler to keep the dust off the rear window. A friend of mine bought a new Suburban. Liked the MPG. Put on the bug deflector and rear spoiler and lost 4 MPG!!! Took him a while to figure out what was going on! When he figured it out he decided to do without the accessories and wash the windows more often!



Steve

______________________

2001. 5 QC 4X4... LOADED

 

[RedRamer]

leimmmo

I agree because I'm sure my mileage went up if I'm no pulling the trailer. I had 2 long trips and both averaged 27. 5mpg Cdn gls.

But this is pulling a travel trailer. Might be something mechanical, who knows.

I'll post the results when I pull with it and without.

goober

 

[raiste]

Have you changed the fuel filter lately? A clogged one will definetly lower mileage.