Tire Pressure Question . . .

. . .with a tropical spin!

I was in the Cayman Islands and I rented a car just to be able to get
away from the tourist zone a couple of times during the week.

Whenever I travel I tend to bring a tire gauge - even to check the
pressures on a rental! Sure enough, the pressures on the car I had
were between 5 & 6 lbs below the label on the door of my Suzuki
Swift. When I asked the rental attendant if more air could be put in
to bring it up to Suzuki's recommendation, here was his reply:

"I normally have my staff keep 28-29psi in all the cars because the
ground is so hot down here that the higher pressures could warp the
rims."

Well, this car had between 20-25psi in the tires, so I compromised,
and went to a station and put 30psi all around, early in the morning.
The handling isn't great, but it's better than where it was!

Folks - is this true - for tropical areas to lower the tire pressures
a little to "preserve both tire & rim" due to the very high year round
temps??

-ChrisCoaster

ChrisCoaster wrote:
> . . .with a tropical spin!
>
> I was in the Cayman Islands and I rented a car just to be able to get
> away from the tourist zone a couple of times during the week.
>
> Whenever I travel I tend to bring a tire gauge - even to check the
> pressures on a rental! Sure enough, the pressures on the car I had
> were between 5 & 6 lbs below the label on the door of my Suzuki
> Swift. When I asked the rental attendant if more air could be put in
> to bring it up to Suzuki's recommendation, here was his reply:
>
> "I normally have my staff keep 28-29psi in all the cars because the
> ground is so hot down here that the higher pressures could warp the
> rims."
>
> Well, this car had between 20-25psi in the tires, so I compromised,
> and went to a station and put 30psi all around, early in the morning.
> The handling isn't great, but it's better than where it was!
>
> Folks - is this true - for tropical areas to lower the tire pressures
> a little to "preserve both tire & rim" due to the very high year round
> temps??
>
> -ChrisCoaster

Hotter than Texas?
Don't think so.
Sidewall flexing (friction) causes heat.
The more air the stiffer the sidewalls, the less the flexing.
Set the air pressure to maximize tread contact with the ground.

On Wed, 26 Aug 2009 15:38:41 -0700 (PDT), ChrisCoaster
> wrote:

> . . .with a tropical spin!
>
>I was in the Cayman Islands and I rented a car just to be able to get
>away from the tourist zone a couple of times during the week.
>
>Whenever I travel I tend to bring a tire gauge - even to check the
>pressures on a rental! Sure enough, the pressures on the car I had
>were between 5 & 6 lbs below the label on the door of my Suzuki
>Swift. When I asked the rental attendant if more air could be put in
>to bring it up to Suzuki's recommendation, here was his reply:
>
>"I normally have my staff keep 28-29psi in all the cars because the
>ground is so hot down here that the higher pressures could warp the
>rims."
>
>Well, this car had between 20-25psi in the tires, so I compromised,
>and went to a station and put 30psi all around, early in the morning.
>The handling isn't great, but it's better than where it was!
>
>Folks - is this true - for tropical areas to lower the tire pressures
>a little to "preserve both tire & rim" due to the very high year round
>temps??
>
>-ChrisCoaster

You're serious about this?? It's not an early April fools joke??

I've heard a lot of silly tire pressure recommendations, but this is
the silliest yet. Inflate the tire to the proper pressure after you
ahve allowed them to cool down after driving (but at a normal ambient
temperature). The tires are going to be rated to carry at least 36 pci
(cold) and the rims are not an issue.

What might be an issue is tire bruising do to excessive tire pressure
and bad roads. But as long as you keep the cold infaltion pressure in
the proper range, I doubt this will be a problem.

Ed
"ChrisCoaster" > wrote in message
...
> . . .with a tropical spin!
>
> I was in the Cayman Islands and I rented a car just to be able to
> get
> away from the tourist zone a couple of times during the week.
>
> Whenever I travel I tend to bring a tire gauge - even to check the
> pressures on a rental! Sure enough, the pressures on the car I had
> were between 5 & 6 lbs below the label on the door of my Suzuki
> Swift. When I asked the rental attendant if more air could be put
> in
> to bring it up to Suzuki's recommendation, here was his reply:
>
> "I normally have my staff keep 28-29psi in all the cars because the
> ground is so hot down here that the higher pressures could warp the
> rims."
>
> Well, this car had between 20-25psi in the tires, so I compromised,
> and went to a station and put 30psi all around, early in the
> morning.
> The handling isn't great, but it's better than where it was!
>
> Folks - is this true - for tropical areas to lower the tire
> pressures
> a little to "preserve both tire & rim" due to the very high year
> round
> temps??
>
> -ChrisCoaster

> Folks - is this true - for tropical areas to lower the tire pressures
> a little to "preserve both tire & rim" due to the very high year round
> temps??

Amazing how people can be diametrically wrong with the best of
intentions, isn't it?


Significantly low pressure might be helpful in "airing down" for
driving in soft sand (unnecessary for off-roading on firmer terrain)
but it must be done knowledgeably and the tires should be re-inflated
to the proper value before going home on the highway.


Underinflation causes tires to heat up due to internal flexing. This
is an especially bad combination with hot ambient temperatures, high
speeds, and heavy loads, and it's actually possible to damage a tire
that way, to an extent that can bite hard. (Remember the Ford
Explorer/Firestone fiasco of several years ago; that's an extreme
example of what can happen). Words of wisdom may be found on
http://www.tirerack.com/tires/tirete...e.jsp?techid=1
and
http://www.tirerack.com/tires/tirete...jsp?techid=147

If anything, the consistent high temperatures down in the islands
should make it easier for the proprietor to choose and obtain the
right pressure.

I doubt the rim really cares, as long as you don't pop the tire and
drive around on the rim, but tire lifetime as well as safety can be
seriously compromised by underinflation.

Cheers,
--Joe

Paul wrote:
> ChrisCoaster wrote:

>> Folks - is this true - for tropical areas to lower the tire pressures
>> a little to "preserve both tire & rim" due to the very high year round
>> temps??
>>
>> -ChrisCoaster
>
> Hotter than Texas?
> Don't think so.
> Sidewall flexing (friction) causes heat.
> The more air the stiffer the sidewalls, the less the flexing.
> Set the air pressure to maximize tread contact with the ground.

Agreed on all counts. I think the attendant just wanted to have a better
sounding answer than "we never check the dang tire pressures until
they look half flat," even though that's probably the truth.

On Aug 27, 1:39*am, Ashton Crusher > wrote:
> On Wed, 26 Aug 2009 15:38:41 -0700 (PDT),ChrisCoaster
>
>
>
>
>
> > wrote:
> > . . .with a tropical spin!
>
> >I was in the Cayman Islands and I rented a car just to be able to get
> >away from the tourist zone a couple of times during the week.
>
> >Whenever I travel I tend to bring a tire gauge - even to check the
> >pressures on a rental! *Sure enough, the pressures on the car I had
> >were between 5 & 6 lbs below the label on the door of my Suzuki
> >Swift. *When I asked the rental attendant if more air could be put in
> >to bring it up to Suzuki's recommendation, here was his reply:
>
> >"I normally have my staff keep 28-29psi in all the cars because the
> >ground is so hot down here that the higher pressures could warp the
> >rims."
>
> >Well, this car had between 20-25psi in the tires, so I compromised,
> >and went to a station and put 30psi all around, early in the morning.
> >The handling isn't great, but it's better than where it was!
>
> >Folks - is this true - for tropical areas to lower the tire pressures
> >a little to "preserve both tire & rim" due to the very high year round
> >temps??
>
> >-ChrisCoaster
>
> You're serious about this?? *It's not an early April fools joke??- Hide quoted text -
>
> - Show quoted text -
______________________
I kid you not.

I just nodded my head and said, "Oh, I never knew that!". Next
morning I drove to the closest gasstation with air and pumped those
things right up. Steering/handling went up too.

I went only to 30psi(even though 2005 Swift recommends 33psi) because
I didn't want to be held liable for "warping his rims". LOLOLOL!
Heck, they had only 25psi in them so what I put in had to help some.

-CC

On Aug 28, 11:02*am, lugnut > wrote:
> On Fri, 28 Aug 2009 06:55:55 -0700 (PDT), ChrisCoaster
>
>
>
>
>
> > wrote:
> >On Aug 27, 1:39*am, Ashton Crusher > wrote:
> >> On Wed, 26 Aug 2009 15:38:41 -0700 (PDT),ChrisCoaster
>
> >> > wrote:
> >> > . . .with a tropical spin!
>
> >> >I was in the Cayman Islands and I rented a car just to be able to get
> >> >away from the tourist zone a couple of times during the week.
>
> >> >Whenever I travel I tend to bring a tire gauge - even to check the
> >> >pressures on a rental! *Sure enough, the pressures on the car I had
> >> >were between 5 & 6 lbs below the label on the door of my Suzuki
> >> >Swift. *When I asked the rental attendant if more air could be put in
> >> >to bring it up to Suzuki's recommendation, here was his reply:
>
> >> >"I normally have my staff keep 28-29psi in all the cars because the
> >> >ground is so hot down here that the higher pressures could warp the
> >> >rims."
>
> >> >Well, this car had between 20-25psi in the tires, so I compromised,
> >> >and went to a station and put 30psi all around, early in the morning.
> >> >The handling isn't great, but it's better than where it was!
>
> >> >Folks - is this true - for tropical areas to lower the tire pressures
> >> >a little to "preserve both tire & rim" due to the very high year round
> >> >temps??
>
> >> >-ChrisCoaster
>
> >> You're serious about this?? *It's not an early April fools joke??- Hide quoted text -
>
> >> - Show quoted text -
> >______________________
> >I kid you not.
>
> >I just nodded my head and said, "Oh, I never knew that!". *Next
> >morning I drove to the closest gasstation with air and pumped those
> >things right up. *Steering/handling went up too.
>
> >I went only to 30psi(even though 2005 Swift recommends 33psi) because
> >I didn't want to be held liable for "warping his rims". *LOLOLOL!
> >Heck, they had only 25psi in them so what I put in had to help some.
>
> >-CC
>
> What Mr. Rental Car hadn't thought about was how many tires
> it was going to cost him to protect the wheels from whatever
> damage caused by overloaded micro-vehicles, bad roads and
> abusive drivers. *Of course, in the Cayman's, you probably
> can't drive far enough at one stretch to really overheat
> tires like we do gere in the States. *Overload is another
> story. *AFAIK, most manufacturers including vehicle
> manufacturers still recommend using a higher inflation
> pressure for continuous high speeds.and/or heavier loads.
> This is to reduce sidewall flex and the heat generated by
> sidewall flex. *If the weather is really hot, you would also
> want to maintain a higher inflation. *If a tire is starting
> with under inflation, it may reach both higher temperatures
> and higher inflation pressure than it would have starting
> cold with more appropriated higher inflation pressure. *With
> OEM recommended tires, it is safe to stay with the
> recommended pressure.
>
> Lugnut- Hide quoted text -
>
> - Show quoted text -
_____________
Hey, the only person I don't agree with here is the agent who
inspected the car with me and signed it off to me for 5 days.

Would he agree with any of you? Probably not.

The only way I can see how one of his cars got a "warped" rim was
because he keeps his yard's tire pressures too low, and a tire burst
during a rental and the rim spent too much time on the road or went
off the road after the flat and hit a curb or rock or something.

BTW for anyone here who has driven Grand Cayman, I personally feel
that the PSLs on their main roads seemed WAY too high - 40 in most
spots, inluding West Bay road(parallel to 7 Mile Beach, and the loop
around the East End, past Morrits Tortuga club and up to Rum Point.
That's what most people were doing though - 35 to 40mph, so that says
something about the CONSERVATIVEly set PSLs here in Uncle Sam's.
Here, folks will do 40 whether the speed limit is 25, 30, or 40.

I'll bet there's no speeding tickets issued there - unless someone
tries really hard(!), but making a right turn across West Bay Road
anywhere from just north of Georgetown up till West Bay Town is a bee-
yotch!! I mean, you're waitin' forever, remember, traffic closest to
you approaches from your right, and traffic in the lane you are
crossing over to approaches from your left. As soon as the right
looks clear, a friggin freight train of cars approaches from your
left. You're waiting five to ten minutes to make a right turn onto
West Bay Road!!

I said screw it, so I turned left, headed north, then when traffic
thinnned out I made a U-ey(illegal!), through the mutual turn lane in
the middle, to my right to get going southbound towards G-town.

It was my first trip driving a RH steering wheel on a LH street, but I
learned a lot.

-CC