6x4 -6x2 mpg

6x4 is a standard tandem drive
6x2 is a tandem drive configuration but only one axle (usually the rear) drives> This configuration is more fuel efficient as you are only turning one set of crown and pinion gears.

 

We are seeing almost a one mpg increase running the single rear axle trucks. Same load weight and terrain as our 6x4's 90% interstate, I doubt that you would see much differance with local or regional runs with a lot of stopping and starting. JMO

 

We've got one 6x2 and it absolutely kills tires. It was built to be light (which it is) but at the rate it kills tires I'm not sure any added fuel mileage would cover the tire loss. The only way it is worth it here is the added payload plus any fuel might cover the tire costs.

It's a W900 daycab with a C12, dead axle and super singles. It pulls a grain hopper and does all short hauls. No matter how easy you let out on the clutch it will slip the drive tires in gravel. You can dump the air off the dead axle which is required when empty but doesn't help much loaded since it bottoms out the suspension so both axles still carry the weight.

If you were OTR it MAY pan out, If you can benefit financially from the added load capacity also helps but if your paying someone to convert a truck hoping to pay for it with fuel savings it may take a long while.