My 1998 Grand Cherokee Limited 5.9L is not a heavy duty truck, but a few
years ago I replaced the original 225/70SR16s with Pirelli 255/55VR16
Scorpio Zero sport truck tires because I liked the lower, wider look. Big
mistake!---Not only did the Pirellis wear out very fast, I lost a great deal
of directional stability at all speeds probably due to the wider tire (
regardless of inflation pressure and four wheel alignment was checked
repeatedly). Since then went back to original size in 225/70SR16 Michelin
Cross Terrain SUV tires. The Michelin were probably the most expensive tires
in that size range from Tire Rack but I'm well satisfied---they have
excellent traction in rain and snow, wear like iron, and got all of the
original directional stability back and more. Been a fan of Michelins since
1963 when I replaced the original equipment bias-plys on my Corvette with
Michelin radials--fantastic improvement in handling and traction (rain and
snow) and they lasted more than six months.
Read an excellent technical paper a few years back (can't remember the
reference) on automotive and aircraft tires---said series 70 tires start
hydroplaning at a MPH = 9.8 times square root of the inflation pressure.
Wider tires start hydroplaning at lower speeds.
Lance
----- Original Message -----
From: "DrMayf" <drmayf@teknett.com>
To: <land-speed@autox.team.net>
Sent: Friday, February 04, 2005 8:06 PM
Subject: Non LSR Truck Tires
> Well, the general consensus is Michelins. One thing I don't understand
> though is the sizes. My truck rides on tires from the factory and they are
> LT265/75 R16 and most say to use 235/85 sizes. Why is that? 235 is
narrower
> and with more siewall (more rolling resistance, less economy). I surfed
the
> Bridgestone/Firestone site and the tires originally installed do not seen
to
> be available any more and the 265 size is hard tolocate. My 265's were
also
> load range E and max pressure of 75 psig so with a wider tire could carry
> more. Right now, one is flat so not carrying anything. Are anyof the
> Michelins 265s? I'll look...
>
> mayf and thanks for the help, ya'll
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