Stock 17's to 20inch rims mpg difference

[ROGELIO A GUZMAN]

Hey fellas. So I have a 04 xl awd 6.0.

So I only drive this beast for long drives and family outings. Currently it has 20 inch chrome rims that the previous owner had bought. I was wondering if I go back to the oem 17inch, would I see a change in mpg's. I know alot of you guys have swapped rims in your trucks. Any feed back would be great.

Goal is to increase 2-4 mpg if possible.

 

[TollKeeper]

My belief on this, if the rims and tires are of the same size overall, and nearly the same weight combined, it should not affect fuel mileage as you are not increasing the rotational mass.

When I weighed a 20" rim and tire, that was the same overall size as my 17 inch wheels, although 1 inch wider, the weight was only 14 ounces heavier. So would I see a decrease in fuel mileage, possibly, but not likely, as 14 ounces, although combined is 56 oz (4lb 8oz), it takes nearly 85lbs to see a difference, and even at 85lbs, the fuel mileage is 0.05 mpg, or less.

But there is a rub, a 1 inch wider footprint creates a bit more drag, aka rolling resistance, then you multiply that to each wheel position. So here I would see a more calculatable difference in fuel mileage. This is a harder mathematical equation as things change with tires, tread pattern, ply, siping, and alignment. Some tire manufacture do make Low Rolling Resistance Tires. But for me, the jury is still out on whether or not these actually make a difference.

IMHO - The only way to get 2-4 MPG increase on these big behemoths, slow down, dont go above 55 mph, and hyper mile it. I personally saw a 4-6 mpg difference slowing down from 75-80 mph to 55-60.

 

[ROGELIO A GUZMAN]

Makes sense. I'm pretty sure the 20 inch rims on my truck are pretty heavy. And for sure the tire is wider. So I think I'm going to start with going back to 17's and getting the correct tire width. I just reached out to black bear performance about a tune. But living in California I don't know if it will affect smog.

 

[Fubar0715]

On my old Tahoe-I saw about 1.5 mpg loss when moving up in wheel size. In my situation, I moved from the stock 265/70/16 to 285/50/20 with no change in driving style. Although, running with my foot hanging out of the grill doesn't help improve mileage, it sure was cool to look at over stock appearance and handled much better, IMO. So, take all of that with a grain of salt cuz I am no expert although I play one on TV...

 

[TollKeeper]

Can I see a pic of the 20" rims you currently are running @ROGELIO A GUZMAN ?

I am currently contemplating upgrading to 20" wheels, so I can do a 2 inch drop, and not have spindle hang.

 

[ROGELIO A GUZMAN]

Can I see a pic of the 20" rims you currently are running @ROGELIO A GUZMAN ?

I am currently contemplating upgrading to 20" wheels, so I can do a 2 inch drop, and not have spindle hang.

I'll take a pic when I get home. Some old 20 from 2014..lol

 

[Joseph Garcia]

As stated above, there may be minimal changes in gas mileage, solely from a change in tire rim diameter, but not the changes that you are looking for.

The only to achieve a consistent 2-4 mpg increase is to change your driving habits. I have proved this time and time again, as I can easily achieve a 2-4 mpg increase by simply having my wife in the truck with me, when I drive.

 

[TollKeeper]

I can easily achieve a 2-4 mpg increase by simply having my wife in the truck with me, when I drive.

Are you saying you drive like a mad man? or she drives like a mad woman?

 

[Joseph Garcia]

Are you saying you drive like a mad man? or she drives like a mad woman?

I'm the mad man driver, for sure. And, yes, if I don't drive as she would like me to drive when we go somewhere together, she rapidly becomes the mad woman, until I adjust my driving habits immediately.

My wife is the slowest (and probably the most careful) driver on the planet. Even my 91 year old mother drives much faster than she does. If I have to go somewhere with my wife, in which we both must take our own vehicles (like taking and dropping off a vehicle at the shop for service), I just drive to the destination and wait for her to eventually show up. I tried the 'drive real slow and keep her in sight in the rearview mirror' method several times, and that failed miserably every time.

The bitter irony for her is that she is the most recent one of the both of us to receive both a ticket from an police officer (not for driving too slow), and being involved in an accident (not her fault). I remind her of this every time that I have the opportunity (and then duck), when she starts to talk about my driving habits. (I probably just jinxed myself!).

 

[TollKeeper]

My wife doesnt complain about my driving.. Other than to say OH $HIT! when I floored the Esky for the first time with her in it.

But I get what you are saying. I have not had an accident, or ticket, in a VERY long time. She totaled the Aztek in 2017 (I rebuilt it), and got a ticket.