I've narrowed my rear tire selection to the ever popular 285/40/18(27"). I like the look of the cars running 245/45/17(25.7") fronts but can't help but think the taller 255/45/17(26") would be a slightly better match to the rears. I can't find pictures of cars running this tire that have been lowered. Is anyone running these with 17x8 torq thrust II and 4" back spacing on a lowered car? Any reason the 245/45/17 is so popular?

 

I made my tire choices based on 2 assumptions:

1. Tires that would fit the above rims (SLP 17's) with no modifications.
2. Tires that would not effect the speedometer and could not be a smaller diameter in the rear than the 255/60/15's since I already have 3.70 gears and going smaller would effectively increasing the numerical gear ratio (go higher) than the stock 255/60/15 which are 27 inches.

The fronts above are 255/45/17 ZR's (26.1 diameter) and the rears are 255/50/17 ZR's (27.1 inches) and to me are the perfect size for my C3 and fit with no issues or rubbing. I would have preferred 255/45/17 ZR's (but wanted to keep the rear overall diameter of 27 inches for the reason mentioned above) all around but the lowered front stance actually enhances the C3's posture since the many C3's including my 78 have a tendency to always look like the rear sits lower than the front. My tire choice fixed that issue. These tires transformed the 78's ride, steering response, and handling since ultra high performance tires are far superior to the crap 15 inch tires offered for our cars made of superior softer high traction rubber, very strong sidewalls that have to withstand ultra high speeds (ZR rating-W/Y speed rating 168/186 MPH), and built with modern tire technology versus an S rated tire like the radial TA, Firestones, Coopers etc.

Hope that helps!

 

I did find your car in another thread but it doesn't appear to be lowered. Would that make any difference in your fit? Do you have any better pics of the front tires? It's hard to get a good look in that pic of the fronts. What's your back spacing also? Thanks



QUOTE=jb78L-82;1591089730]

I made my tire choices based on 2 assumptions:

1. Tires that would fit the above rims (SLP 17's) with no modifications.
2. Tires that would not effect the speedometer and could not be a smaller diameter in the rear than the 255/60/15's since I already have 3.70 gears and going smaller would effectively increasing the numerical gear ratio (go higher) than the stock 255/60/15 which are 27 inches.

The fronts above are 255/45/17 ZR's (26.1 diameter) and the rears are 255/50/17 ZR's (27.1 inches) and to me are the perfect size for my C3 and fit with no issues or rubbing. I would have preferred 255/45/17 ZR's (but wanted to keep the rear overall diameter of 27 inches for the reason mentioned above) all around but the lowered front stance actually enhances the C3's posture since the many C3's including my 78 have a tendency to always look like the rear sits lower than the front. My tire choice fixed that issue. These tires transformed the 78's ride, steering response, and handling since ultra high performance tires are far superior to the crap 15 inch tires offered for our cars made of superior softer high traction rubber, very strong sidewalls that have to withstand ultra high speeds (ZR rating-W/Y speed rating 168/186 MPH), and built with modern tire technology versus an S rated tire like the radial TA, Firestones, Coopers etc.

Hope that helps![/QUOTE]

 

[/QUOTE]

I don't have a better picture in photobucket so sorry. The SLP rims are no longer made but were specifically made by SLP to fit C3's at the time with zero fitment issues...I believe the correct backspacing from what I have read for our cars is 4.5mm but others can verify that figure. The front springs in that picture are midamerica 550 replacements that were suppose to be 1 inch shorter than stock. The rear has a VBP 360 monospring with Bilstein Sport shocks...the composite has been on the car since 1986 when no one had a composite spring on a c3 if it wasn't an 81/82.

 

245/45/17 are popular because there are a lot of choices. It's a standard size for many cars.

I like to match the tire size front and rear. What about using a 255/45-18 in the front to match the rear diameter.

I'm using the 255/45-18 on the front and rear. Sometimes I wish I'd done the 9.5" but too late.

 

I considered an 18 up front but slighly preferred the 17". Probably splitting hairs. I'm hoping someone chimes in with with this exact combo.

 

FWIW...I would go 18's today and think that the 255/45/18 ZR's would be the killer setup....better tire selection today in the 18's

 

I think that is what I will do. As I yet do not have a C3 (soon) I don't know what the widest wheel I can use on the back is. Would say a 9.5" or maybe a 10" work on the back and a 8.5" on the front? I'm still a little confused about all the backspace and offset stuff. The wheel stores do not make it any easier.

 

Here is 17x8 and 18x9 245-45-17/275-40-18, widest rear tire with stock trailing arms and body work is the 285. depending on your back spacing/off set you may have to relocate the e brake. Some say you an get a 275 on the front without rubbing but you have to be very precise with your measurements.

 

Nice Color....not many C3's have our colors....

 

Thanks, I need to get rid of those pin stripes but they are under the clear.