Today I saw a Jeep Grand Cherokee SRT8 and the back tires were massive at 285-40-20

They are the same diameter 29" as the SRT8 Challenger.

The Challengers 255-45-20 are only 8.5" tread look small comared to the Jeeps 10".

Do you think the 285-40-20 will fit the rear of the Challenger as the first replacement set?

 

Let's see. Who would I ask this question to? A professional at, say, a tire shop or a bunch of people who like to speculate on internet ...?

 

And what tire shop have you ever experienced "professionals" regarding performance cars and tires?

There is some amazing talent on these threads e.g. Andre who has been incredible in his upgrades.

I have had great luck with tirerack on hi performance tires, but don't think they have encountered Challenger potential mods.


Let me rephrase my question to 2 parts

1 How much room in the wheel wells for wider tires?
2 Has anyony tried bigger tires yet?

 

Sorry. I've always been more interested in looks than performance. When my associate and I used to street race our 68 Coronet 440 Magnum, we always put crappy tires on to keep the RWL Goodyears so they didn't get wrecked up. Generally, we still won.

 

Well, just going by width, the 285s are 30 millimeters wider than the 255s. Converted to inches, that would be 1.18 inches wider. Thats all I can do on my end, as I do not have an SRT8 to crawl under to measure to see if there is ample clearance for an inch or so wider tire.

 

I know that there is room for wider tires on the rear of the Challenger, but the SRT engineers advised me that if you go wider than a P245 on the front, you will encounter clearance problems with the front suspension under extreme handling conditions.

 

All I know is the speed rating for tires is 186 for Challenger SRT8...If you put on 160 rating tire mfg voids warranty....just a thought .

 

Yeah... its too easy to run this thing past 160...

 

I heard that is Top end for a RT....

 

That's correct. The top end speed is governed by the computer. The SRT does not have this restriction and can hit 173 mph.