Short wheel base, soft suspension and soft sidewalls on corner exit on the gas, the 90 squats big time unweighting the front end feels like an easy way for an unassisted roll over.
But we all drive differently and I'm just giving my 2cents since I have a 90 but I'm on 305/50/20 BFG 32", I didn't want something I know is the wrong way to go if I'm gonna be on the highway before I get to the dirt..

 

Looks great!
I like the 20s too.
I had pretty much written off the idea of being even able to drop down to the 18s till I saw some P400s running 18s .

I was planning, or leaning towards going with some rims like this.
These are a 20x9.5 +25 offset





Been researching here on the forum rather the 285/55R20 or 275/55R20 would be best on a 100% stock suspension without rubbing and without any trimming.
‘I like the 285 width the best.

I see you went 305s how is the fit on your setup?
What offset are you running?

 

I love this wheel and tire size combo.
I would love to know more about this setup.
Were there brake mods needed to get these 18”s on the P400?
Lots of post stating brake mods required to fit 18s onto P400s and P525s?

 

Damn I wouldn't want to clean those rims. Stock wheels with a 30mm spacer on the rears only..zero rub

 

This owner had the rear calipers trimmed.

A very simple mod to allow fitment of a variety of 18" rims on P400 (most of them, unless they were factory built on 22")

They have a thread documenting their process.

There are other similar ones and a good write up from saltek motorsports on their website.

I run 18" rims on my P400. Calipers trimmed.

 

‘Thanks, that’s great into.
‘Sounds like since mine is P525 and all P525s come standard with the 22s, that’s going to be a bigger problem ever getting 18s fit on it.
Sounds like I am just SOL on being able to fit 18s with that simple caliper shave mod.

Which I have shaved calipers to fit rims in the past, not a big deal, just kind of a dirty job, but not hard to do at all.
I think my 21 GMC AT4 was the last time I had to give the front calipers shave to fit the custom wheels I had bought for it.

I guess I better stick with my plan to find a 20” rim I really like and get either 275/55R20s or 285/55R20s.
‘Seems like lots of conflicting info on those tire sizes as what rubs and what doesn’t.
‘Which I can only assume it’s likely differences in offsets, or possibly one tire brand or model vs another.

‘So anyone have expertise or thoughts as to
+25 offset 20x9.5 what will clear, and be flush with the fenders 0 poke stance.

‘Which tire 275/55R20 or 285/55R20 or something different ?

 

‘To drop down from the stock 22s I have to buy rims anyway, no plans of buying spacers too.
I am ok with the stock 32” tire height I just want optimal flush stance , and more of an AT tire with in a more common size and more sidewall then the stocks 22”s would ever allow.
I defiantly don’t like any poke, not only because it through dirt, mud, and rocks at my car, it also throws stuff at others.

Best I can tell so far is my OEM Rims are 22x9 with a +43 offset.
The + 25 offset in a 20x9.5 should push my tire right at 1” which I am concerned is going to creat some poke?
+43 - +25 is difference of 18mm which translates to 0.71 inches plus the 0.25” the added .5 inch width gain causes,
Total added stance 0.96” per wheel
. Basically adds about 2”s of track width,

 

I'd go 265/60 R20 no lift. Max tire height at about 32.5" so check the actual tire dimensions rather than nominal sizing. KO2s will fit in this size.

I run a 32.6" tire 265/70 R18. Nothing to spare in access height. Nada. It fits but only just. Offset is +29mm on my rims.

 

Dumb question, that would void the warranty right away, correct?

 

if there were problems with the rear calipers they would not be covered under warranty.

All else remains unaffected.

I’ve got about 35000 miles on the vehicle since the trim and about 3000 left in my factory warranty.

plenty of warranty repairs have been done.