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Will Continental 305's fit on 10" Wheels?

Has anyone tried the Continental 305/660/18 GT-R's on 10" rims? I've used 285/645/ GT-O's on them and it looks like they might be able to take a slightly larger tire but I do not want to spend the money until I'm sure they will fit and be safe. For comparison, the tread and section width of the 285's are 10.625" & 11.562" respectively vs 11.375" & 12.250" on the 305's. The 305's are essentially .75" wider than the 285's.

If anyone has experience with these tires any feedback would be appreciated.

General Question - If they will fit on the 10" rims is it safe to run on a road course with a tire that is 2.25" inches wider than the rim? Will this have a negative effect on the sidewall and potentially compromise the integrity of the tire?


Grant 302

basic and well known psychic
A 10" wide rim is actually over 11" lip to lip. So the fit may not be as bad as you're thinking.

I wouldn't run them that way, but I don't see any problems aside from sidewall flex if you use them on the rear axle.


Supporting Vendor
i run the conti 305/660R18 GT-O on my 10" wide all round. you can check them out on my car next month! i think they work very well....just not at anything less than -3 camber.

actually, at the track this weekend, i met up with a crew member for one of the IMSA Continental Series for an ST car. His shop also crews for one of the Camaros. He wasn't 100% sure, but he thought they might be running the 305's all around, but with a staggered wheel width. he thinks they are 10 front and 10.5 rear. I asked him to call me when he gets back to the shop this week to confirm this because i had the same concerns about the tire being to wide for the wheel.


Too Hot for the Boss!
I've been running the 305/650s for two years now on 18x10 wheels without issue. They want camber, and they want the correct tire pressures. Other than that, they work very well for me... other than me killing off a set at Hastings :(

With the 18x10 D-Force wheels, I do not need a spacer up front or out back.

With the 18x10 Drift wheels, I need a 5mm spacer up front and nothing out back.
pufferfish- what were your findings at running them at less than -3 camber?


Supporting Vendor
Steve: Conti's sweet spot is 36 hot. They degrade slowly until 40, where they turn greasy.

The imsa crew member I met over the weekend confirmed that's what works for them too.

Doc: Running less than -3 just resulted in mid-turn under steer. Can't say what tire temps were across the tread though.


Too Hot for the Boss!
With my setup, 31 front, 29 rear COLD gets them about perfect by the first hot lap. Most of the tracks I'm at either have long pit-in routes which negate after session checking <or> I'm sprinting to catch my student in the next session.

With camber, I'm at -3.3*...this definitely saves the outer edge of the tires and seems to even out the front wear. They also do not like if you are a drift-tard on track, the rears will shred and cord pretty quickly.

Bill Pemberton

0ld Ford Automotive Racing Terror
Exp. Type
W2W Racing
Exp. Level
20+ Years
Blair, Nebraska
Crap, now that John Scheier is giving people all this valuable information, it is going to be hard to call him a Cheatin Bastige anymore.

PS - John I have 305s in the rear, 285s in front and I have destroyed them too ---- trying to stay ahead of you, ha,ha.

Thinking more and more that I need to run the SBY Laguna , kinda miss running with all you wackos and pretty sad that I probably will not be able to make Hi Plains this year.

John is a great instructor, talented driver, and has alot of track miles under his belt, so you can go with his thoughts, just say an Amen , as they be gospel !!
The bulge of the 305's on the 10'' compared to the 11'' is quite evident but nor SOOOO bad :)


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