On my 18x9.5 +38s I run 245/45 285/40 rear, if I were to do it again I'd run 255/45s up front as there's pretty good room up there.

 

went back and looked, i like that

 

I run 255's on my front wheels which are 9.5", and like Brad said there is plenty of room for them. No rubbing in the 7 -8 years I've been running that size up front. But they are a bit too stretched for my taste, so I plan to switch to 275's up front, which is about as wide as I can go on the 9.5" wheel (maybe 285's but I'll start with 275's - baby steps ), sometime in the near future.

 

In looking at that chart, the 18x9.5 +38 seems to be the best fitament. I'd love to try 275/40 square, but I'm sure 255/45 and 285/40 staggered would work too.

Now that I have 295's in the rear with vastly improved handling, I do wonder if I'd be taking a step backwards in that department. Lighter but less tire patch.

 

FYI... Here's a pic of some new rubber that I just received... $140 each! Closeout deal from TireRack! These aren't for the G though.

 

Yeah Adrian, I got the same basic deal $136 per for the 285/40s, made it a no-brainer

What are those for, that German beast??

 

Your post was what made me look for them. Thanks! I can get sponsorship pricing from Toyo now, but that Tire Rack deal was just too good to pass up.


Yup, good call, they are for the Porsche.... It's up on jack-stands right now getting a whole new suspension (I mean everything!), big front Brembo brakes with 2-pc rotors & braided lines, new rear brakes, new tires, etc... I was also able to find a pair of 245/35R18's in the same tire locally for the front. They were also a good deal, but not as cheap as Tire Rack has them for.

 

Forgot to ask.. Are the 285/40's the ones you are running on 9.5" wide wheels? I was a bit worried that the 285's would be too wide for my Porsche wheels (also 9.5"), but after seeing your pics and seeing (and measuring) the tires it looks like a 9.5" wheels is just about right for the 285.. maybe a 10" wheel would be ideal, but the 9.5" is pretty close to perfect.

 

Yep, they're on the 285s, it's a bit funny since my front 245s are the narrowest tire width recommended for that 9.5 and the 285s are the widest tires recommended for that width wheel. I've ripped around a bit so far and they seem to be holding up well, and the grip is really good. It seems that a 10.5 is the "perfect" mount on that 285 but I'm happy with the fit.

 

Would 11s fit in the back with 295s + stock camber lowered? Offset is not a problem (wheels I'm thinking are +55). Other option for the wheels are 10s but I'd rather go wider. I like the safely stretched look.

 

is your g37 sedan Awd?

 

His is RWD, and his build thread here for specifics~
https://www.myg37.com/forums/build-t...a54-sedan.html

 

11" wheels will fit, but with the 55 mm offset your will probably need to add a spacer in order for the inside of the wheel to clear the traction rod and shock. I know from experience that a 10-1/2" wheel with 45 mm offset just barely clears, so figure in that your 55 mm if going to be 10 mm further in, plus another ~6 mm (for half of your extra 1/2" wheel width) and these wheels will probably need another 15 - 20 mm of clearance.


My rear wheels are 10-1/2" with a +37 mm offset and without my spacers I only have about 1/2" of clearance on the inside of the wheel, so I'm not sure a 10-1/2" wheel with a +55 offset will ever work without spacers.


Keep in mind, though, you'll definitely need to run quite a bit of negative camber (or heavily stretched tires).


Here's a handy dandy wheel offset calculator that will help you determine offset/clearance based on tire size. Based on this calculator a 295/30R30 on a wheel with a +55 offset would be about 0.9" closer to the suspension than my old set up which was a 285/30R20 on my wheels with a +37mm offset (which as I mentioned above didn't have nearly this much clearance).


https://tiresize.com/wheel-offset-calculator/

 

I'm in the market now for some new rubber on all four corners. I've got the stock duckfeet sport wheels. What is the absolute most meat I can get away with? Stock suspension as well. I'm in Texas so I'll also be buying some hardcore summer tire. Maybe YOKOHAMA or TOYO

 

Unfortunately the front duckfeet being only 7.5" wide you're locked into a pretty narrow range, a 235/45 or 235/50 would be about it, in back on that 8.5" a 255/45 or 255/40 is about as wide as I'd recommend.