How can I improve MPG?

[Wade Haines]

I own a 2018 Ram 3500 single wheel crew cab. Installed a lift with some 35's on 18" wheels. I've had these trucks dating back to the early 90s and always had lifts on them which I know eats a mile or two per gallon, but my mileage is really not good at all. Any suggestions that won't void warranty?

 

[BWL]

Drive a prius

 

[kurek]

Did you also correct the truck's speedometer for the new tire size?

 

[sandawilliams]

Only drive downhill with a tail wind.

 

[Neil E]

Don't drive over the speed limit. Easiest way to get better gas mileage.

 

[Judy]

If you are worried about MPG, don’t get a hemi

 

[mtnrider]

What kind of mileage are you seeing? And is it hand calculated and have you calibrated your speedometer to the larger tires?

Honestly not much you can do with a 8000lb truck on larger tires. Even deleting isn't going to buy you much on these newer trucks. Best thing you can do is keep it under 65-70 mph on the highway, avoid stop and go traffic etc.

My 2500 cummins with 35's and level kit is getting around ~16mpg running around town (which is rural driving for me, no city stop and go traffic) and mid 18's on the highway but I'm running 75-80. If I slowed down that would go up. The 2500 with the 68RFE transmission will get slightly better mpg then the Aisen in the 3500.

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[Wade Haines]

Drive a prius

Looking for solid info. Thanks for the smartass reply.

 

[Wade Haines]

Looking for solid info. Thanks for the smartass reply.

 

[Wade Haines]

Don't drive over the speed limit. Easiest way to get better gas mileage.

 

[Wade Haines]

I don't recall saying anything about driving over the speed limit..

 

[Wade Haines]

Did you also correct the truck's speedometer for the new tire size?

 

[Wade Haines]

Haven't done that yet. What would be the easiest way to do that? Thanks for your advice also. WH

 

[kurek]

I asked about calibrating for the new tire size because if the truck still thinks it has stock size tires then the odometer is still giving you miles traveled for the stock tires. If your tires are 10% bigger you're traveling 10% farther than you think and getting 10% better mpg than you think.

Also shift calibration is based in part on road speed and likely affects efficiency so making sure the vehicle knows how fast it really is going can only help with fuel efficiency

There are a bunch of tire size calibration tools, most are $100-200 and they plug into your obd port and let you enter your tire info. I think alfaobd does that too, it's only $49 plus the Bluetooth dongle but it also has hundreds of other uses so may be the best deal

 

[Wade Haines]

I'll start by doing that, makes a lot of sense thank you so much for your help

 

[BWL]

Manufacturers spend a fortune to maximize their fuel economy. Best you'll get is leaving it stock and driving in the most fuel efficient way. Driving over the speed limit costs you mpg on the highway due to the amount of wind drag these trucks have.

 

[mtnrider]

You still haven't said what kind of mpg you are getting now? That would be helpful.


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[Wade Haines]

Pulling my large 5th wheel, 10-11mpg. It should be doing better. I'm going to calibrate the bigger tires which I had not done yet oh, that might add a mile or two to the average indicator.

 

[BWL]

Pulling my large 5th wheel, 10-11mpg. It should be doing better. I'm going to calibrate the bigger tires which I had not done yet oh, that might add a mile or two to the average indicator.

That may also correct the shift points and engine mapping and give you a little boost in mpg.

 

[gfh77665]

Definitely keep your tires aired up to the max pressure specified. Drive easy, coast to stops. Reduce MPH by 5 whenever possible. Condense trips. Do all of the above and you will see a significant improvement.

https://procarmechanics.com/how-tire-pressure-affects-mpg/