Help: Will a 305/65/R18 fit on 18 2500 stock height and wheels

[SixFOURhemiHD]

Time has come to replace the junk OEM Firestones on my 18 2500 6.4 Hemi with 4.10s. Already settled on the Cooper Discoverer AT3 XLT, just deciding on the size. First question is, can I run a 305/65/R18 on stock steel wheels at stock height? Will it run? And does anyone pave photos of their truck running stock with this size? Second, how much of a hit will I take in mileage? Diameter is nearly the same, but the 305 had much more tread contact and is 8lbs heavier than the stock Firestone 275/70/R18s. Third, same questions as above for a 295/70/R18. It’s a little taller, also is 59# vs 51#, but not as wide. Lastly, on the 305, it’s rated as an E2 old range, so it can support max weight at 65psi. How is the ride on that compared to the E1 with 80psi max. I currently run 60FR/50RR to get a good full contact patch. Thanks for the help.

 

[MADDOG]

The stock wheel is an 8x18.

Cooper recommends a minimum/maximum wheel width of 8.5"/11" for the 305/65R18.

For the 295/70R18 they recommend a minimum/maximum wheel width of 7.5"/10".

You'll also want to be mindful of the width of the tire to avoid rubbing with the stock wheel offset in place.

As far as mileage I have no idea although an increase in unsprung weight and width will have a small negative impact but no where near what towing or poor ambient conditions (wind rain snow) will have on mileage.

The ride won't be as bad but obviously you don't need to run at max psi all the time with either tire unless you are towing heavy.