View Single Post
Old 06-11-2011, 03:54 PM   #11 (permalink)
bwilson4web
Engineering first
 
bwilson4web's Avatar
 
Join Date: Mar 2009
Location: Huntsville, AL
Posts: 843

17 i3-REx - '14 BMW i3-REx
Last 3: 45.67 mpg (US)

Blue Bob's - '19 Tesla Std Rng Plus
Thanks: 94
Thanked 248 Times in 157 Posts
Quote:
Originally Posted by larrybuck View Post
I have an '87 CRX. I have 175/70/13's now.
. . . frustrated that I'm turning 2,200-2,300 rpms at a mere 50mph.
. . . I don't have the scratch for high dollar LR tires,
. . . I need at least 2 better tires to even be safe.
. . . a size common enough to be easily found used anywhere!
I've tried to reduce your requirements to a common set.

Sumitomo T4, low rolling resistance tires, Tire Rack price does not include shipping, mounting and balancing.
175/70R13 - 1,036 lbs - 51 psi - 927 rev/mile - $52/ea
185/70R13 - 1,135 lbs - 51 psi - 907 rev/mile - $60/ea
If you go with oversized, Sumitomos, you need to read the specs on the rim width to match your wheels; the tread width; and the overall diameter. Take a string and ruler and measure where your current tires sit relative to the wheel well. Make sure there is enough clearance before buying.

If there is any question, consider buying one tire to mount on a spare wheel and then put it on the rear and test drive over some speed bumps. Then swap to the front and again test over some speed bumps. The one tire test approach is somewhat expensive because if you by a second one, more shipping cost. Worse, if the tire doesn't work out, getting credit back will entail some loss. But then you'll know for the second one.

Double check the Sumitomo T4 reviews against your likely driving. They are not listed as being good on ice and snow but that is what winter tires and chains are for.

Having two tires that won't pass inspection suggests there may be an alignment problem. Start with an analysis of the wear pattern and follow-up with a measurement and alignment. Also, find out if your car has adjustments for:
  • front toe - pretty much universal
  • front camber - ?? sometimes requires a camber bolt
  • rear toe - ?? fixable with metal tabs or EZ-Shim
  • rear camber - ?? fixable with metal tabs or EZ-shim
If you do get an alignment, get a copy of the new values and start a fresh thread about '4 wheel alignment.' This is a different problem from the tires.

There are web sites that claim the best tires should be on the rear to prevent the car from spinning out in marginal conditions. However, I found that having a pair of different sized tires, they should be tested in one configuration and then swapped, front-and-rear. Check the handling and maximum effort braking in sane conditions and choose what works for you.

GOOD LUCK!
Bob Wilson

__________________
2019 Tesla Model 3 Std. Range Plus - 215 mi EV
2017 BMW i3-REx - 106 mi EV, 88 mi mid-grade
Retired engineer, Huntsville, AL

Last edited by bwilson4web; 06-11-2011 at 04:07 PM..
  Reply With Quote
The Following 2 Users Say Thank You to bwilson4web For This Useful Post:
California98Civic (06-11-2011), larrybuck (06-13-2011)