Running 305-70-16 on Mickey Thompson rims. Did not notice any difference in gas or performance and love the look.

 

Yeah, they're 33's so ground clearance would be the same.
It's sidewall flex that I was commenting about. 325/60/18 has a tire sidewall of about 7.6 inches vs. a 315/75/16 which has a sidewall over 9.3".
More tire sidewall = more flex = a softer ride.
With less tire sidewall you WILL get a stiffer ride and you will feel every pothole, speedbump, and rock much more than a tire with more sidewall.
Serious offroading and airing down a 60 aspect tire is a whole other issue.

 

but you are comparing a 33 to a 35. I can't run 35's because I use it to travel alot. I have a Suburban for my play toy. 33's are as big as I am gonna get for a while. I want wider rims and I hate buying aftermarket rims that are the same diameter. it is a whole lot easier to buy tires for 18's than 17's. I know by experience. Around here you get sand and mud with an occasional rock for offroading on.

 

mine are 33x12.50x18 on 8.50x18 wheels Ilike them alot. Only drive drive about 10 miles aday ride is nice

 

What size Toyo's are you running?

 

I have 35s on the PW and may bump up to 37s at some point, but for my dd H3 I am not going much bigger than stock. Maybe a size bigger. I drive almost 100 miles a day just to and from work.

 

The Toyo's are 315/75/16

 

Love the look of your truck! I want to go with that tire/wheel size. What width 18's are those and what's offset? In your photo album you state that they are 35's. Here you say they are 295's. Are they the same?

 

Guess that's the best foreign tire crap can look????? Doh.

 

I would stick with 33's......especially an I5....I am running 35's on my Alpha and have seen a dump in fuel....wifey is driving around town and this week it clocked 12.88 MPG...at $3.70 it gets me about 4 days to the office. I used to get about 18 with the factory Dueller's