[cmjohnson]

Maybe a dumb question. I did search, and didn't seen the answer. On the first gen CTS, what rim size(s) were provided on the sport version of the car? I'm asking because it seems likely that I'll be seeking out a set, since I have begun to run in autocross events.

Currently I have the regular 16" rims (225-55-16 tire size) and I want to go up to a slightly larger rim size, but I want to stick with Cadillac original rims. But I've read that the sport size rim is 17 inches, and I've read that it's 18 inches. It has to be one or the other, or maybe they were available in both sizes? That's what I need to know.

I also want to go to a wider tire size, and also maintain the factory spec tire diameter, or at least very close to it. I'm open to going to as wide a tire as won't rub when installed. I'd like to go to at least 245 width tires.

The stock 225-55-16 tires are 25.7 inches tall. 245-50-16 would be 25.6 inches tall.

In 17s, the oem size tire is 225-50-17 which is 25.9 inches tall. 245-45-17 would be 25.7 inches tall, and so would be 275-40-17.

I'd have to check to see what width is the max that will run without rubbing at a max deflection turn.

My reason for wanting to go to a larger (wider) tire is simply a matter of traction. Very important when driving an autocross course.

I want a set of autocross rims and tires, in addition to my regular daily driver OEM 16s. Not really interested in aftermarket rims, thanks but no thanks. I like to preserve the authentic Cadillac look in everything.

I've already upgraded to V sway bars, which helped stiffness in cornering a lot, and in fact I did that upgrade as soon as I got the car, two years ago. There is a strut brace that will fit under the 2004 luxury package hood, and I need to just go ahead and buy it. It's pretty cheap, but you have to get the right one. There are not less than three different strut braces for a first generation CTS and I know for a fact that two of them don't fit. Because I bought both of them based on bad information, and no, they DON'T fit. The LS9 marked brace is too low and rubs on the intake, and the other one is too high and won't let the hood close as it's meant for a bumped-out hood in a later model year.

I recently replaced the soft ride FE1 front struts with FE2s, but left the original springs in place. I'm scheduled to change out the rear struts for FE2s very soon. I may also change out the springs. I don't want to go to TOO stiff a ride as this is my daily driver and I like reasonable comfort.

 

[pleese11]

http://www.automobile-catalog.com/tire/2007/335945/cadillac_cts_3_6l_v-6_automatic.html

 

[cmjohnson]

Thanks for that! Does anyone here have definitive proof of the largest size tires (width) that will go on the front
of a first gen CTS? I get the idea that the listed tire sizes may all fit on the back, but not all can be assured of fitting
up front.

I want to run the widest tire size that will work on both front and rear.

[You don't have to hit ENTER when you get to the end of the white text entry box. Just keep typing and the magical auto word wrap will take care of you, like so:]
Thanks for that! Does anyone here have definitive proof of the largest size tires (width) that will go on the front of a first gen CTS? I get the idea that the listed tire sizes may all fit on the back, but not all can be assured of fitting up front.

I want to run the widest tire size that will work on both front and rear.

 

[Jon]

The '03-04 Sport package had 17" rims.

The '05-07 Sport Appearance Package had 18x8 rims. Factory tire size was 225/50/18. I run 245/45/18 tires, which is the same as the V size. I have a full V suspension and it will rub the plastic fender liner a bit at full lock. Very minor; it's just a touch. When I went to a V bumper and V fender liners it seemed that it rubbed less. My CTS-V does not rub though.

The largest tire you can fit is going to depend on the offset of your rims. If you want to run the 18x8 Sport Appearance rims with a +44 offset I wouldn't go wider than 245.

The STB you want is the one found on the '05-07 Sport Appearance Package. It's the same as the one from the '06-07 LS2 powered CTS-V. I have that on my '04 3.6L and it clears the engine cover and hood fine.

 

[AAIIIC]

Maybe a dumb question. I did search, and didn't seen the answer. On the first gen CTS, what rim size(s) were provided on the sport version of the car? I'm asking because it seems likely that I'll be seeking out a set, since I have begun to run in autocross events.

Currently I have the regular 16" rims (225-55-16 tire size) and I want to go up to a slightly larger rim size, but I want to stick with Cadillac original rims. But I've read that the sport size rim is 17 inches, and I've read that it's 18 inches. It has to be one or the other, or maybe they were available in both sizes? That's what I need to know.

As Jon said, there were both optional 17" and 18" wheels.

I also want to go to a wider tire size, and also maintain the factory spec tire diameter, or at least very close to it. I'm open to going to as wide a tire as won't rub when installed. I'd like to go to at least 245 width tires. ...
My reason for wanting to go to a larger (wider) tire is simply a matter of traction. Very important when driving an autocross course.

I want a set of autocross rims and tires, in addition to my regular daily driver OEM 16s. Not really interested in aftermarket rims, thanks but no thanks. I like to preserve the authentic Cadillac look in everything.

I'm confused. Do you want to run the widest tires that will fit under the car, or do you want to arbitrarily restrict yourself by only running narrow OEM wheels?

I run 275/35-18 R-compounds on 18x9" wheels all around for track events. I have no rubbing issues, even with the car lowered 1-1.5" on coil-overs. You should be able to run 275/40-17s all around, but not on OEM wheels.

 

[cmjohnson]

I'm probably going to find out, but initially I was guessing that the 8" wide factory wheels would be
wide enough to take the widest front tires that will fit. That may not work out. But honestly
I'm not really interested in aftermarket rims. That's never been my style so I will most probably
restrict my tire width choices to what's suitable for the OEM rims that I eventually choose.
Cost is also a factor as I'm not exactly "well heeled", so not going for the super widest range of
tires will help keep this affordable.

I'm also going to be asking the question, at some point, what type of tires I should be getting,
once I've settled on a size range. I usually buy Michelins but they get very expensive in the kind of
sizes that I'm contemplating, so I may opt for a lower cost tire brand that is still a great choice for
autocross. I would not object to any recommendations on this subject.

With unnecessary hard returns removed:
I'm probably going to find out, but initially I was guessing that the 8" wide factory wheels would be wide enough to take the widest front tires that will fit. That may not work out. But honestly I'm not really interested in aftermarket rims. That's never been my style so I will most probably restrict my tire width choices to what's suitable for the OEM rims that I eventually choose. Cost is also a factor as I'm not exactly "well heeled", so not going for the super widest range of tires will help keep this affordable.

I'm also going to be asking the question, at some point, what type of tires I should be getting, once I've settled on a size range. I usually buy Michelins but they get very expensive in the kind of sizes that I'm contemplating, so I may opt for a lower cost tire brand that is still a great choice for autocross. I would not object to any recommendations on this subject.

 

[Jon]

I'm probably going to find out, but initially I was guessing that the 8" wide factory wheels would be wide enough to take the widest front tires that will fit. That may not work out. But honestly I'm not really interested in aftermarket rims. That's never been my style so I will most probably restrict my tire width choices to what's suitable for the OEM rims that I eventually choose. Cost is also a factor as I'm not exactly "well heeled", so not going for the super widest range of tires will help keep this affordable.

I'm also going to be asking the question, at some point, what type of tires I should be getting, once I've settled on a size range. I usually buy Michelins but they get very expensive in the kind of sizes that I'm contemplating, so I may opt for a lower cost tire brand that is still a great choice for autocross. I would not object to any recommendations on this subject.

If cost is a factor you're going about this the wrong way. It's also impossible to recommend anything without knowing your autocross experience and what level you want to compete at.

If you're planning to autocross all season long and compete, you're much better off buying a set of r-comps for your 16s. They're going to be cheaper than a set of 18s, and also cheaper in the long run as you burn off a couple sets. Buy a set of 18s for the street as that's what you'll have on the car most. I learned to autocross in my '04 3.6L before I progressed to my other cars. 225 vs 245 is not going to be noticeable in this car on an autocross. Seat time will give you a much bigger advantage than 20mm will. Again, I don't know what level you are competing at. I ran 245/40/18 Hankook slicks and Toyo R888s on my CTS-V for autocross. The limitation that I ran into wasn't front end grip, but the chasis and weight. My bone stock '14 CTS Vsport on factory tires has less grip than my '04 CTS-V on slicks, but it will destroy my '04 at autocross. You can see how I did here: http://www.cadillacforums.com/forums/cadillac-v-sport-general-discussion/699169-autocross-results.html

Point I'm trying to make is, 245 vs 225 isn't going to impact your times much IMO as you're limited by the rest of the car.... And the guy behind the steering wheel.

 

[cmjohnson]

I am new to autocross. Very new, in the sense of going to organized autocross events. I've spent some time
driving in a large abandoned housing project area that never made it past the street paving phase, which has
given me some experiences that have helped me to learn more about controlling the car, but I am definitely
still a beginner by any standard.

Learning where my money would be best spent would of course be very welcome.

My long term plans are to buy a Porsche 911, or at least a Boxster, and use that for all autocross
and other "fun" driving and keep the CTS for daily driving duties, but that's a long way away.

With unnecessary hard returns removed:
I am new to autocross. Very new, in the sense of going to organized autocross events. I've spent some time driving in a large abandoned housing project area that never made it past the street paving phase, which has given me some experiences that have helped me to learn more about controlling the car, but I am definitely still a beginner by any standard.

Learning where my money would be best spent would of course be very welcome.

My long term plans are to buy a Porsche 911, or at least a Boxster, and use that for all autocross and other "fun" driving and keep the CTS for daily driving duties, but that's a long way away.

 

[Jon]

I am new to autocross. Very new, in the sense of going to organized autocross events. I've spent some time driving in a large abandoned housing project area that never made it past the street paving phase, which has given me some experiences that have helped me to learn more about controlling the car, but I am definitely still a beginner by any standard.

Learning where my money would be best spent would of course be very welcome.

My long term plans are to buy a Porsche 911, or at least a Boxster, and use that for all autocross and other "fun" driving and keep the CTS for daily driving duties, but that's a long way away.

In that case your best bet is to learn autocross on your stock 16s and burn off the rubber on those. Buy 18s for the street.

It's much better to learn on street tires as they are more predictable and give you a better feel of what your car is doing. As you get more seat time and improve your ability, get grippier tires. Starting with sticky tires is a bad idea imo as you'll overdrive your car. Best thing you can spend money on by far is seat time. Followed by brake pads and tires.

 

[Submariner409]

Here's a pair of 2003 Sport 17" wheels - clearcoat/polish, same size as the last 3 years of Seville Touring Sedan - which had the chrome version. High positive offset, 17 x 7.5", 235/55/17 tire.

I picked up 4 of these for $300, shipped, a while back and use them for my Z rated high performance tires - the Caroline County farm road twisties tires.

Click a thumbnail to enlarge, use your browser <-- to back out.

 

[KevMS]

If in the future I've got to really good 07 performance package 18 inch rims, and 2 fair 07 PP Rims. The edges need refurbishment. Will let them all go cheap, if anyone can use them