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1996 Buick Roadmaster wagon wheel & tire size

2480 Views 29 Replies 8 Participants Last post by  ayilar
Hi! I'm new to this forum and just purchased a low-mileage '96 Buick Roadmaster wagon. I want to get some Torq Thrust II wheels (or something similar) but don't know whether to go with a 16", a 17" or an 18" (figure on them being 8" wide). I want the wheels/tires to fill the wheel well for a modern version of the classic look. The wagon will be a cruiser and I have no intention right now to modify the suspension. Which diameter wheel is BEST supported by the aftermarket? What is a reasonable width to look aggressive but not rub the fender lips? What offset should I look for?


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If you want to fill wheel wells without rubbing fender lips or modifying the suspension ...
Anything wider than 255 will not fit in the spare wheel well, and will rub the sidewalls against the inner rear fender lips (the ones you can't see from outside unless you get UNDER the wagon).
To fit a 255/70R15 in the spare wheel well of my wagon I had to deflate it first.
When I needed a spare, reinflating it before installing it was a pain in the ass.

Fix Until Broke is generally correct about 29" tall tires being the tallest tires that can fit without modifications.
235/75R15 is 29" tall, and is the OE tire size for Cadillac Fleetwood limos.
(There's a thread where he explains what he had to do to install 31" tall tires.)

255/70R15 - 5 tire options (several ISSF members use without issue, classic meaty fatass tire)
255/65R16 - 8 tire options
255/60R17 - 4 tire options
255/55R18 - over 50 tire options
255/50R19 - over 50 tire options
255/45R20 - over 50 tire options
255/40R21 - 8 tire options

18" wheels will cause less suspension stress than 19" or 20" wheels.
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255- width tires work fine in any 18" wheel between 7"-9" wide.

Note Fix Until Broke's pic.
The rear of his 31" tall 255/55R20 tire is tight to the body at the back of the tire.
He did NOT just stick 'em in, he paid quite a bit of attention to the suspension to fit them in.

255/55R18 (29.04" tall) will fit inside all four corners just fine - if the ISSF's history repeats itself.
However, note that 255/55R18 may NOT fit in the spare wheelhouse without deflating it.
235/60R18 (29.10" tall) will fit in all 5 positions with no issues. (Most similar to OE for limos.)
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... picked up some Torq Thrust's in 17" x 8", because that's the Impala size ...
Thanks. I went with the Impala size tire; 255/50R17.
The 18" equivalent of the OE Impala SS tire size would be
255/45R18 - 27.04" (255/50ZR17)
The 18" equivalent of the OE wagon tire size would be
255/50R18 - 28.03" (235/70R15 for 2.93 wagons or 225/75R15 for 2.56 wagons)
The 18" equivalent of the OE limo tire size would be
255/55R18 - 29.04" (235/75R15)
255mm of width and 29" of tire height is about as much fat tire meat that can get stuffed in without modifying suspension parts.
For some reason I thought my wheels at 17x8, 14mm positive offset were the Impala size, but I was mistaken.
I haven't had any rubbing yet, but I had to park my Buick for the winter shortly after I had the wheels and tires installed, so I don't have a lot of miles on the combo.
I noticed that there are a lot of options in 255/45R18, which has the exact same footprint as the Impala size tire.
Plenty of well performing options for
as well.
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