Not too long, very good, great infact - thanks. Will keep same size.

"Circuit Breaker" > wrote in message
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> On Fri, 21 May 2004 23:45:54 -0400, Andrew Perlow wrote:
>
> > Any opinions on 90 Spirit tire size change from 185/70R14 to 195/60R15?
> > Is it worth the cost of new wheels?
>
> I'm with Dan. It's probably not worth it.
>
> At best, I would expect maybe a slight drop in fuel use at highway speed
> *IF* the overall diameter of the tire rubber is larger. But if my math
> is correct, they're not.
>
> IIRC, the first number is tire width in millimeters, the second the
> percentage of that number that the sidewall measures, and the third
> being the rim diameter in inches (or the diameter of the inside hole of
> the tire, effectively the same thing).
>
> 185 * .70 ~ 130mm. 130 / 25.4 ~ 5.1 inch sidewall. times 2 (one for each
> side - make a diameter instead of radius), is 10.2, plus 14 for the rim
> diameter is 24.2 inches overall diameter.
>
> 195 * .60 = 117mm. 117 / 25.4 ~ 4.6 inch sidewall. Times 2, 9.2. Add
> 15, is 24.2 inches overall diameter.
>
> Hmmm. Seems to me you would have no gain whatsoever beyond simple
> cosmetics. You tell us. Is it worth it?
>
> FWIW, I have 205/60R15s I think. That makes them 24.7 inch overall
> diameter, so there's not much difference there, either.
>
> OTOH, you have to consider handling as well. You will have a different
> contact patch which may be larger or smaller depending on the weight your
> vehicle places on them. If you have a lighter vehicle, you'll want
> narrower tires. Heavier, wider. Otherwise, you wind up with a car
> that's so light it doesn't flatten the tire to the road for a proper
> patch, or so heavy it wears out the tires too quickly. In addition, the
> sidewall affects cornering ability, as it's a flexible piece of the
> suspension. I might consider changing all that for racing, but not for
> street driving. Even doing 70 mph up a 35 mph 270-degree circular onramp
> to an interstate highway like I sometimes do won't bring you anything
> that you'll notice much change in. Shouldn't be going that fast anyway,
> I know.
>
> Overall, if you don't race your car professionally or at least in some
> form of amateur circuit, don't spend money on rims. If you're going
> purely for cosmetics, consider the junkyards. Seriously. I purchased
> two rims from two yards. Both snowflake. Each rim got a fresh tire and
> replaced the donut spares in my car and my friend's car. One cost $20,
> the other $7 (yards vary, shop around). So now, for $27 and the cost of
> 2 new cheapo tires, I wound up with 2 perfectly good full size spares.
> 205/60R15. Assuming $20 for each rim and $40 (guessing) for each tire,
> you're looking at $240 to replace all four, $300 if you include a spare.
> You'll be lucky to get new rims alone for that price around my area.
> YMMV.
>
> Hope this has helped somehow. I know it's rather long (my trademark) but
> hopefully it answers your previous questions and helps answer future
> ones.
>
> Good luck
>
> CJ