Re: Low Rolling Resistance Tires

["Patrick Warner" <fyrehawk_69@hotmail.com>]

There are numerous trade offs involved in tire design, the two biggest being 
tire-life vs. Traction, and rolling-resistance vs. traction (Not the same 
way).  The first comparison is between "Hard" and "Soft" Rubber, softer 
rubber giving better traction, but not lasting as long.  The other 
comparison is between Large and small tire footprint (not only the tire 
width, but also the diameter) A smaller tire overall will have a lower 
rolling resistance due to the decreased friction area, but there is also 
less rubber in contact with the road and under ideal driving conditions less 
traction, but higher psi in the existing tire patch area, and so better 
traction in inclement weather.
So, after all of that, what would be the best for an EV?  Given generally 
slower speeds, and shorter trips, the smallest "Long-Life" tire you can 
find.  You can always replace the speedometer gear in the tranny to account 
for the smaller tire diameter in your speed.
As for Air-Springs, they are "AWSOME", and I wouldn't use anything else.

Patrick Warner
Still in the design phase of my own 3 wheel EV...

>From: Edward Rupp <edwardrupp@netzero.net>
>Reply-To: ev@listproc.sjsu.edu
>To: ev@listproc.sjsu.edu, ev@listproc.sjsu.edu
>Subject: Low Rolling Resistance Tires
>Date: Thu, 30 Mar 2000 21:48:19 -0800
>
>Hi folks,
>
>I've been searching for info on tires, and haven’t found much comparison
>info.  Also checked the list serv archive, didn't find much.  Is there
>any web sites that go into detail?
>
>The tires on my RX-7 are looking close to bald.  I just bought Steven
>Richardson’s EV pickup, who’s tires are needing replacement.  So I’m
>going to be spending a lot on tires and would like to get the best range
>performance I can get.
>
>So far the only tire brand that seems to mention having  low rolling
>resistance tires is Goodyear.  The Decathlon seams to have the narrowest
>tire available that will fit my car.  The RX-7 now has P185/70R13.  The
>Decathlon has P165/80R13 and P175/80R13.  The other model line is the
>Invicta which has a P185/70R13.
>
>I would think the narrowest tire available would be the most efficient,
>however I’m not certain I might be overlooking problems with the
>slightly different tire height.  Also I’m not too certain what to do for
>tires for the pickup.  It seems the tires for pickup’s don’t have any
>great concern for energy efficiency.
>
>Has any one noticed a big difference in range using the “fuel economy
>tires”  and what model did you use?
>
>Also researching Air Springs for the pickup.  Has any one used these
>critters?  They seem the most versatile way to beef up a suspension.
>
>Would much appreciate some advice.
>
>Edward Rupp
>EV addict
>Mazda RX-7 EV
>Mitsubishi EV PU
>Loveland Colorado
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