Wheel/Tyre Question

Anonymous · Post by **Anonymous** » Tue Oct 17, 06 3:50 pm

Ok so here's my next stupid question guys.

I currently have 235/60/14's on the rear of my car. What's the tallest/widest combination of wheel & tyre I can fit without having to modify the body?

I was thinking about maybe going to 17's to solve my rev/speed/diff problem out.

What do you think of these?

Blue · Post by **Blue** » Tue Oct 17, 06 4:54 pm

Hate 'em! I think you'll have trouble finding "tall" tyres in 17", they tend to be low profile, your best choice will be in 15". As regards size you'll have to get the tape measure out, to cram the maximum amount of tread in you'll need to choose a wheel that comes in more than one backspace (offset) or can be ordered in a custom backspace. The common backspace for most wheels is 3.75" regardless of width which is about as much use as chocolate fireguard whan it comes to Dart rear wheel wells.

BUDGIE · Post by **BUDGIE** » Wed Oct 18, 06 7:58 pm

Orrible! If you go 17" you MUST decrease tyre side wall height to maintain the correct/existing rolling radius.

AllKiller · Post by **AllKiller** » Fri Nov 17, 06 11:14 pm

What is your rev speed diff problem then ??

Anonymous · Post by **Anonymous** » Sat Nov 18, 06 12:21 am

I've got 3:55 gears and that with the 235/60/14's I'm currently running means I'm only doing 58 mph at 3000 rpm.
I'm relocating to Scotland...eventually! and these kinds of rpm/speed ratios will make the car even more unpractical due to the distances I'll need to travel.
The easy answer would have been to change the gears and I thought I had. Was under the impression I had 4:11's but once it had been taken apart we found out the truth.
So that leaves us with the easiest and cheapest option of fitting taller/wider tyres to gain 12/15 mph at 3000 if I fit 255/75/15

Alex · Post by **Alex** » Sat Nov 18, 06 8:50 am

Check tyre heights and go from there, mine are 28" tall and it will cruise at 80 all day long. (it has 3.55's as well)

MilesnMiles · Post by **MilesnMiles** » Sat Nov 18, 06 9:32 am

There are calculators for this on-line. Sorry, not sure where, but i've used them in the past. Tyre height x rear gear ratio x rpm/speed. Much easier than offering up various combinations of wheels and tyres.

AllKiller · Post by **AllKiller** » Sat Nov 18, 06 9:56 am

Your old tyre height is 25.1 inches

your suggested 255x75x15 tyre height is 30 inches slower take off speed bigger top end but you will lose a little response lower down in speed, but the side wall is high and will induce bounce and wallow

255x65x15 will give you 28 inches in tyre height and and a better sidewall profile and better allround gearing for your car.

Anonymous · Post by **Anonymous** » Sat Nov 18, 06 9:57 am

Dave very kindly sorted me out with an online calculator. I have found it to be very useful

http://challenger.mpoli.fi/the.dodge.ch ... Cchart.xls

I've also found this lot for cheap tyres

http://www.formula4.co.uk/

Just need to get the measuring tape out now!

AllKiller · Post by **AllKiller** » Sat Nov 18, 06 10:08 am

these are cheap for tyres and free delivery too.

http://www.camskill.co.uk/images/main-logo.gif

AllKiller · Post by **AllKiller** » Sat Nov 18, 06 10:09 am

these are cheap for tyres and free delivery sometimes too

http://www.camskill.co.uk/products.php?plid=m4b0s0p0

or these

http://www.blackcircles.com/