Rear Tire Size Pros/Cons - Advice Please

[Wavey]

Car is an '88 Carrera.

I have a set of 7X16 and 8X16 Fuchs at Al Reed's right now, getting refinished. I'm going to have Tire Rack drop-ship a set of Yoko AVS ES100s to him.

I'm going to use the stock tire size, 205/55 on the 7X16s for the front.

I'm trying to decide whether to go with the stock 225/50s on the back, or switch to 245/45s. I've searched and found a bunch of pics of carreras with the 245/45s on the back and they look a little small, diameter-wise, compared to the fronts. They're only 1/2 inch shorter but it's a visible difference. But I like the extra tread width of the 245s (over an inch).

Obviously, I'm suffering from my normal excessive fretting and terminal indecision, so I give up. What do you guys think?

Thanks!

Dave

Option: go to a lower profile front tire (205/50) with the 245 rears?

[dd74]

Well, the smaller diameter might help the gearing a bit. I think I'd stay with the 50 series you had earlier. Their 225 size is correct for an 8-inch rim. 245 is sort of wide IMO for 8 inches.

[Bill Verburg]

For looks the 225/50 may be ok(if you like that sort of look, I don't)

For performance the 245/45 is the ticket. lower the car if the gap is too big.

[Wavey]

Originally posted by dd74
Well, the smaller diameter might help the gearing a bit. I think I'd stay with the 50 series you had earlier. Their 225 size is correct for an 8-inch rim. 245 is sort of wide IMO for 8 inches.

Yeah, I looked at that - the 245s are OK for rim widths of 7.5 - 9". I kind of like the idea of slightly lower gearing.

I guess my dilema is the visual difference front-to-rear if I go with the 245s.

Thanks...

[dd74]

Wavey, if I were going to use the 45-series tires, then I'd go with 50s up front. I think the discrepancy between 55 and 45 might be just flat out strange looking - like a dragster in reverse or something. It stretches the aesthetic.

[KTL]

Here's an idea.

If you don't like the fat sidewall look of the fronts, then change those. Go with a 205/50-16 or 225/45-16?

[Wavey]

Originally posted by dd74
Wavey, if I were going to use the 45-series tires, then I'd go with 50s up front. I think the discrepancy between 55 and 45 might be just flat out strange looking - like a dragster in reverse or something. It stretches the aesthetic.

Exactly!

Here's a pic for reference, with I believe 205/55s up front and I know 245/45s on the rear (my appology to whoever's car this is - not trashing your car, just a personal preference issue):

[teatray]

tire sidewall height

245 x .45 = 110.25 mm

225 x .50 = 112.50

205 x .50 = 102.50

205 x .55 = 112.75


50's are too small on the front. the 55's match either of the two rears wrt to sidewall height.

my pref is for the 245's.

[Bill Verburg]

50's are too small on the front

NOT! 205/50 on 7x15 and 225/50 on 8x15 was the factory optional setup on my C3

Side wall height is not a critical issue. Most cars are set up for close to equal rolling radius though. Variations of an inch are quit common and acceptable.

205/55 or 225/50 or 225/45 are alkl god 16" matches for 245/45

7" or 8" +23.4mm o/s fronts and 8" or 9" rears are good, wider is better.

[hobieboy]

FWIW - factory 930 uses 205/55/16 in front on 7" rim and 245/45/16 on 9" in the rear. I know many on the track uses 225/50 in front but if its for street use, I think the benefit may not be noticeable at all.

Don't forget rim width also comes into play here. A 225/50 front with 7" won't give you much increase in contact patch compared with 205/50.
Ditto with the rear.

[bigrubberjeep]

For those of you in this thread - could you please show your pictures of wheels and tires other then Fuch?

[Bob's Flat-Six]

Here's 245/45 rear with 205/55 up front but riding lower than the white 911. The tires are Bridgstones SO3's.

I just measured and the sidewall and the 245/45 is about 3/16's shorter from the ground to the wheel lip than the front 205/55 with a full tank of gas and correct air pressure.
Edit: the tires in the rear are newer than the fronts, but the tread depth is close on front and rear.

[ZOA NOM]

9's in back. They look identical to the 8's from the outside. The extra inch is inboard. The 245/45/16 most closely matches the factory circumference for speedo accuracy.

[Wavey]

Wow, excellent responses! I'll have to digest this for a while. I'm mainly looking to get similar sidewall heights front and rear, not as concerned about the actual aspect ratio. But wider is better on the back, so...

Bob's Flat Six - that could be my car, Dansk and all, except for the headlight rims. Sweet!

The guys on this board are the best. It's great to post such an anal question and be understood.

[jazzbass]

Check out this site:

Tire Calculator

Nice little applet that allows you to compare tire sizes and get sidewall and diameter measurements.

[bigrubberjeep]

oooohhhhh that picture of the black center fuch give me the chills - just what I will do on mine -

[Bob's Flat-Six]

Pretty cool site , Chris

[89911]

Here are various fuchs on my car for comparison:

205/55 front on 7x16"


225/50 front on 8 by 16" 951 rim


225/45 front on 8 by 16" 951 rim


245/45 rear on 9 by 16" rim

[Sonic dB]

I have 245/45s on the rears (9s)...and 205/55s on the fronts (7s).

The 245/45s do look a little thin and definately added much space to the rear wheel well. The car now needs to be lowered for sure.

If I had to do it all again, Id choose 245/50s for the rear.

You will love the AVS ES 100s btw....

[Wavey]

Originally posted by 89911
Here are various fuchs on my car for comparison:

Jeez, 89911, is that the best you can do? :> Thanks for the pics - helps a lot!