17 in to 20 in

[Charger]

Hi Guys , don't know if this is the right place to ask but.... I bought a 04 1500 4dr SB 4x4 , love the truck. From what I found out it came with 20 wheels and is rated at 8500 lbs towing . I have a 5300 lb camper, The PO took off the factory 20 in tires and wheels and put on 17 in. If I go back to 20 in , how will this affect gas mileage and towing? As it stands with the 17 in When I'm 45 mph on the speedo I'm actually going 42. Thanks

 

[mtnrider]

Wheel size has nothing to do with it, it's the tires you put on those wheels that will effect mpg, towing, mph, etc. You can get tires for the 20's that will be the same height and width as what is on your 17's now. Sound like the tires on your 17
s now are smaller then factory if your speedo is reading faster the actual.

.

 

[HemiLonestar]

Tire height will be your deciding factor, though 20's are heavier so it's more unsprung mass to get rolling. Since it is highly likely the PO didn't adjust the speedo, it's probably still set for stock tire height. Beautiful thing is, with a tuner that can be easily adjusted for whatever tire size you choose or anyone with a DRBIII can adjust it. If you find yourself in northern MD I can do it.

 

[Marley]

If you did what I did , you'll feel a slight decrease in towing capacity.....lifted on 35's but I only tow 5K.

I went to an 18" wheel .

Assuming you have the 5.7, it won't care, it'll drag 5300 with ease but will drink a lot.

 

[ST-8]

Me being a lowered 2wd having 17s stock then going back n forth between the 2 size rims, biggest thing I noticed was the braking an not much acceleration. Deff could tell right away it needed more pedal to stop.