Where to find an accurate tire pressure gauge???

Matt Whiting wrote:

Damn, Matt!!

Just a week or so ago, you were arguing with me when I suggested going
outside the manufacturer's recommendations on oil viscosity - after all
- how could I know more than the engineers who designed it? But now you
want to go outside the mfgr.'s recommendations on tire pressure.

What the hell's wrong with you!!?? 8^)

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

 

I'd have to go back and re-read my posts to be sure, but I don't think
that is what I said. I said that I didn't think that staying WITHIN the
manufacturer's recommendation of 5W-30 viscosity oil would shorten your
engine life. I don't think I said anything about not using oil outside
that range. Personally, I don't for the simple reason that an engine is
an expensive component to experiment with, whereas tires are relatively
cheap. I can get fairly good tires for my van for less than $400 a set
and even if my experiment increases my wear by 25%, I'm only out a
hundred bucks or so. For me, that is a reasonably amount to risk on an
experiment. The cost of replacing an engine isn't within my range
personal range!

Although, I am experimenting now with my 96 minivan. At the 150K mark I
decided to switch from 5K oil change intervals to 10K, still using
Mobil 1. The van owes me nothing so it is now within my experimental
range!

I did the same with a 79 Chevette when it reached 100K miles. I'd used
Mobil 1 (actually Delvac 1) since 50K when I bought it from my parents.
I really didn't care if I ruined it after 100K (actually was kind of
hoping it would die!), so I decided to go 10K between changes. I sold
that car with something like 130K on it and the person that bought it
wrecked it just shy of 150K and the engine was still going strong.

So far, my minivan is doing the same and is just about to roll over 170K.

I'm an engineer. I can't help it!


Matt

 

I agree with you Matt. I put tires on my minivan that are 44 psi max
and 205 instead of 195, tiny bit wider but more choices to choose from.
I run them at 39 psi, so with highway speed, +4 mph, they are around 43
psi when hot. It may be cutting it too close but I get a better ride
and better handling. Recently I made a mistake or the dealer did and I
noticed a very bad ride and handling. I thought it was because I had
too much air in the tires. Turns out they were low at around 31 psi
cold. The actual sticker says 35 psi so I figure the 39 psi is a little
over, 10+%, but seems just fine for me, especially since I run the van
light. That is, no rear seat, not much weight in it at all - and I'm
losing weight! So I would agree with you here. And less tire wear also.

 

Actually you're right - you didn't say that directly, but I do notice
that your response to posters with questions about such things is "What
does the manual say", and I guess i can't argue with that too much.

But I was just reminded by another poster that manufacturer's
recommendations are sometimes absolutely wrong. My example for that
would be a 7000 mile oil change interval for the 2.7L engine -
absolutely the wrong practice with that engine.

I said that I didn't think that staying WITHIN the

I may disagree *IF* that 5W-30 is a non-synthetic. Synthetic? Maybe -
but I have my doubts - nothing catastrophic, but some incremental loss.

It's a curse we both live with. That and our classic good looks!

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

 

Except that I have the 2.7L engine - in which case *not* experimenting
with oil and such would probably be the risky and potentially expensive
thing to do.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

 

The max on the sidewall is a cold inflation pressure and usually will
say that on the sidewall. So you don't need to worry about the pressure
rise with heat as that has already been factored in by the tire maker.

Matt

 

Does the manual really day 7,000 mile intervals for the kind of driving
that most people REALLY do? Doesn't it have a severe schedule? Doesn't
the "severe" description cover how most people really drive?

And svelte figures!

Matt

 

When you go up in size to a larger load group you can actually lower the
pressure a bit. Also, something not mentioned yet, snow tire venders and car
venders usually recommend going +4 psi cold over the OEM tire
recommendation, but not over the max pressure stated on the tire. It is
gross under or over inflation that can cause tire damage, but tire pressure
differences, front to back, also impact handling and some vehicles are very
sensitive to this, but that is another discussion.

Richard.

 

'Most' is not 'all'. I don't think a very high percentage of 2.7's
would survive past 75k on shcedule A under schedule A conditions, and
I've read first-hand accounts (yes - anecdotal) of absolute refusal to
honor the warranty under what was claimed to be Schedule A conditions
with documented Schedule A maintenance. The dealers retort was not that
they checked into the conditions under which the car was actually used,
but that they refused to acknowledge that there was such a thing as
Schedule A driving conditions in the real world. You may say that they
are right, but I'd call that false expectations to publish such a
schedule and then claim that it doesn't exist in the real world. Burden
of proof would be on them to prove that that vehicle was not used under
Scehdule A conditions. It wouldn't take much of a lawyer in today's
leagl system to win that one.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

 

No, it is also true for those cars. I have always run about 5PSI lower
than max inflation pressure (mainly to account for variations in tire
guages)
and never seen this wearing out in the center thing on a passenger car.

Frankly, I've seen tons of tires in wrecking yards and very few show wearing
out in the center first. Just about all of them the center of the tire has
the
deepest tread. With the age-o-lawsuit that we are in I strongly suspect
that max inflation pressures stamped on the tire sidewalls are SEVERELY
derated anyway. Every one of my old tires has worn from the edges first,
but if I inflated them any more I'd be exceeding the tire rating.

And, I have NEVER seen an automaker inflation recommendation that
wasn't a minimum of 10 psi lower than max inflation, and a lot of them
are even lower than that.

Ted

 

How true. I forgot about that. But it's a too harsh ride at 44 psi I
find with my particular minivan. Might be okay if all turnpike highway
speeds and a long drive.

Right from the manual, it says:
If going more than 75 mpg, you must inflate the tire to the maximum
pressure listed on the sidewall. Yup, could hardly believe it:

For speeds in excess of 75 mph or 120 km/h tires must be inflated to
the max pressure specified on the tire sidewall. Page 22-2 of 1994
Chrysler minivans.

The manual also says one must not go above 35 psi for P-Series or
passenger tires of standard load. But since mine were 44 psi max I
gather they are not standard load passenger tires.