Re: RE: Air Pressure/MPG

From: Kevin L. Miller (kmrcdd@swbell.net)
Date: Tue Feb 13 2001 - 21:50:55 EST


I'm sure you're right about driving habits. I don't usually find the need to
speed very often. I'm not familiar with these types of tires & they may be
totally different than what I am used to.(1st 4x4)
I know the main focus of these tests has been MPG & unfortunately (or maybe
Fortunately?) at the time I was running those tires on my GMC I was getting
21-22 & as high as 24 mpg & was satisfied with that. Gas was much cheaper
then so I didnt watch that .
Jacob's opinion as I recall (dont quote me) is that Tire mfgrs don't make
the money selling tires to Auto makers. The real money is in selling you
that next set, & so on. They , along with auto makers want to portray to the
consumer the nice soft ride & comfort, which is important to alot of
drivers.
I look at the psi max rating similar to the date on Milk, that date doesn't
mean that at one second after midnight the night the date passes that the
milk is instantly spoiled. There are windows in which tires will operate
best. You are told to increase tire pressure with the increase in load. So
isn't there much more stress on the tire at 50 psi with 2000 lbs in the bed
than with no load?? If the mfgr says thats ok, then I dont see a problem
with 51 or 52 with no load & normal driving conditions. JMO
----- Original Message -----
From: Sevrence, Sean (S.J.) <ssevrenc@visteon.com>
To: <dakota-truck@buffnet.net>
Sent: Tuesday, February 13, 2001 6:37 AM
Subject: DML: RE: Air Pressure/MPG

> Morning Kevin!
>
> Thanks for the info! It is not just psi that contributes to longevity.
> Driving habits play a large factor. I ran my G-years for 80k at 32-35psi
on
> my first two sets, then I stupidly changed mfg's ('92). Doh! BTW, I'm
ready
> for my only third set of brakes on the '92. Downshifting does wonders!
Yes,
> the clutch is rock solid with plenty of meat on it.
>
> I am starting a test next Monday looking at psi vs. mpg ('01). I am
> surprised that Dr Chris Jacobs suggests going outside of the parameters
from
> the mfg's.
>
> Kevin, have you noticed different tread depths across the tire running
above
> the suggested max?
>
> The test parameters - driving 200miles with 80%hwy at 73mph (otherwise
I'll
> get run over), no hard accels, over two-day period (Monday AM-Tuesday PM)
> Recording psi, average temp and humidity for each day. Repeat for each
psi.
> I'm planning on using 2psi increments starting at 32psi. Any thoughts on
> whether to include the wind speed/direction?
>
> This will take a while to do, but we'll have a nice chart when I'm
through.
> Is there anything else anyone would like to add anything to the test?
>
> Sean
> '92 RC Sport 3.9L 5spd - 250,000mi!
> '01 CC SLT+ 4.7L 5spd 3.92 LSD Mobil-1!
>
> -----Original Message-----
> From: Kevin L. Miller [mailto:kmrcdd@swbell.net]
> Sent: Tuesday, February 13, 2001 2:48 AM
> To: DML
> Subject: DML: Air Pressure/MPG
>
>
> I Heard Dr Chris Jacobs (Jacobs Electronics Founder) on a talkshow few
years
> ago talking about performance & mpg. He said they did testing on many
> different factors relating to performance & fuel economy besides their own
> products. They found the best MPG, tire wear, & longevity resulted from
Over
> inflating tires 1-2 psi over the Mfgr's max. I followed this advice on my
94
> Sonoma w/ Tiger paws. 1st set -got 72,000 miles - at trucks recommended
> inflation. 2nd set of tiger paws (same tire & size) got 97,000 miles. @nd
> 2nd set still had more tread than the 1st did. They weren't in the wear
> indicators yet.The only drawback is ride comfort. I'm currently running my
> 31's at 51 psi. 34000+ miles. No abnormal wear. I dont know how many miles
> these Goodyears are supposed to last. from the tread I have left I
estimate
> 60-70k miles.Time will tell.
> kmrcdd@swbell.net
> Kevin
> 2000 4x4 QC 4.7L auto SLT+ 3.55 LSD Skids ,K&N, MAAP Nerfs, SS bedrails
> Catch-alls, Deflectors, White/Silver 180 TS, Bosch 4418 +4 Mobil-1
>
>



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