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tire pressure?

Posted: December 13th, 2005, 4:57 pm
by luke_himself
hello,

Hi i have A 1995 V6 uk model, i have the standard 15" alloys on and i have no idea what PSI the tires should be, i dont know if youve noticed but its getting pretty greasy here in the uk and this is my 1st winter in the mx3 and the last thing i want is over inflated tires ,

thank you

(sorry for spelling , you get my drift )

Posted: December 13th, 2005, 5:27 pm
by JWMX3
44 psi max if you have stock sized tires

it should say right on the sidewall of your tires

Posted: December 13th, 2005, 5:32 pm
by luke_himself
44, really , front and back i think mine are like 35

Posted: December 13th, 2005, 6:08 pm
by JWMX3
yep , its 44 for the 205-55-15 tire (i always fill mine a bit less then the max)



if you had say a 70 series tire it would only be 35 max psi, and with my old 18's rims with 35 series rubber it was really high about 52psi

Posted: December 13th, 2005, 7:13 pm
by atlantamx3
It should say on the tires... why dont you just look at them?

Posted: December 14th, 2005, 10:02 am
by Nd4SpdSe
atlantamx3 wrote:It should say on the tires... why dont you just look at them?
Or even then, Just play around and see which you like better...I would thing that you would want less air pressure in the winter than more to give better traction in low-grip enviroments.

Myself, In the summer, I put in max air pressure, it stiffens the ride and give me better turning response.

Posted: December 14th, 2005, 12:34 pm
by jschrauwen
JWMX3 wrote:44 psi max if you have stock sized tires
it should say right on the sidewall of your tires
44psi :shock: :shock: :shock: Holy Sh*t Batman!!!!! Hope you don't do that as a matter of practice. To start, a good reference point to begin with is the recommended tire pressure that's in the manual as well as on the inside of the drivers door jam. IIRC, even that label on the door jam is slightly low. At any rate, I'd recommend starting with 31 to 32 PSI and do the confirmation test afterwards. Check pressure of tires while still cold (again start with about 31-32) Do a spirited drive for at least 20 minutes ensuring you're placing a fair amount of demand on the tyres. Quickly check the pressure again while they're still hot/warm. If the pressure rises by more than 3 psi, then your original cold pressure was too low and needs to be bumped slightly. Tyres should be at a pressure so as to be able to get slightly warm but not hot to provide the best stiction. That 44psi is a the max pressure rated for that particular tyre under maximum load conditions. The only way I could see someone needing to have 44psi as a normal setting would be towing a trailer with the hatch full and full tank of gas with 4 people on board. How many of us would ever fall into that category? 205/55-15 = 31/32 psi should be a good starting point.

Posted: December 15th, 2005, 9:56 am
by PATDIESEL
Holy crap is right, 44 PSI is WAYYYY to much!!! J-Beef is spot on, try his method and you should have the correct amount of pressure for the current outside temp. Also the door jamb of the drivers side gives the manufacturers recomended tire pressure.
You guys running 44 PSI must have some aweful handeling. Good steering response yes, but grip would be aweful. You are also most likely wearing out your tures much more quickly since at 44 PSI you'll be running on the center of the tread and not on the whole tread...

I drive pretty aggressivly and notice that my tires fold a bit and the tread on the side (the slight overlap on the sidewall) does get some action. This indicates a perfect amount of pressure for spirited driving and will offer the most traction.

Posted: December 15th, 2005, 10:31 am
by JWMX3
jschrauwen wrote:
JWMX3 wrote:44 psi max if you have stock sized tires
it should say right on the sidewall of your tires
44psi :shock: :shock: :shock: Holy Sh*t Batman!!!!! Hope you don't do that as a matter of practice. To start, a good reference point to begin with is the recommended tire pressure that's in the manual as well as on the inside of the drivers door jam. IIRC, even that label on the door jam is slightly low. At any rate, I'd recommend starting with 31 to 32 PSI and do the confirmation test afterwards. Check pressure of tires while still cold (again start with about 31-32) Do a spirited drive for at least 20 minutes ensuring you're placing a fair amount of demand on the tyres. Quickly check the pressure again while they're still hot/warm. If the pressure rises by more than 3 psi, then your original cold pressure was too low and needs to be bumped slightly. Tyres should be at a pressure so as to be able to get slightly warm but not hot to provide the best stiction. That 44psi is a the max pressure rated for that particular tyre under maximum load conditions. The only way I could see someone needing to have 44psi as a normal setting would be towing a trailer with the hatch full and full tank of gas with 4 people on board. How many of us would ever fall into that category? 205/55-15 = 31/32 psi should be a good starting point.

lol, first of all i fill them 40 , i was telling him the max, 31 psi my tires look flat j-beef !! and im talking when they are warm, common now

Posted: December 15th, 2005, 3:44 pm
by PATDIESEL
Then you need to get the recommended performance V rated tire that the car came with. The higher the rating the more stiff the sidewall generally. The more stiff the sidewall the less flat it will look with a lower pressure. :roll:

This is basic car tech guys, common....

Posted: December 15th, 2005, 3:58 pm
by jschrauwen
Excellent point Pat, on the speed rating of the tire wrt sidewall stiffness. My current low profile tyres (which as we all know doesn't have nearly the same amount of sidewall depth as the 205/55) but has a much stiffer sidewall. I still use around 31 to 32 psi during the spring/summer/fall periods. One note - if car resides outside during extreme cold weather months (or you experience a drastic drop in overnight temp) ensure you make a quick inspection of tyres on that first start-up in the morning. They may appear much lower (especially if they are only H or S rated). It's a good idea to be checking tyres more frequently in the winter than the summer.

Over/Under

Posted: December 17th, 2005, 1:45 pm
by neumann
A lot of good points, particularly about tire profile series variations.

My various tires are all 50 and 55 series and H to W Speed rated so kinda in the middle of the modern tire range but pretty low profile by the standards of when my cars were made.

On these types of tires I usually start at around 34 PSI and go up from there as needed. Usually running in the 34 to 38 PSI range as feels best.

While I do tend to run a little lower in winter and agree that going to somethng like 44 PSI is almost never going to be the right fit on passenger car tires, I think that there are way more cars out there that are dangerously underinflated than there are overinflated.

Most of this is just from not checking often enough. I tend to check all the time and I carry a 12v air pump in each of my cars. I bought one for my GF and last time I drove hers, I pulled over after a couple of miles due to bizarre shudder. One tire was down to under 20 PSI. After filling it i kept track of the leak and it must have taken over a week to get that low. I can't imagine not noticing it.

Some is intentional to soften the ride.

Some ought to be criminal, like Ford telling owners to dangerously underinflate the tires on their SUVs because they designed the suspension wrong and then blaming Firestone for the rollovers.

Posted: December 19th, 2005, 7:35 pm
by Meanie
Anything over 40 is too much. I put 36 psi in mine and have found this to be the best for gas mileage. At my last fillup in partial highway and city, I averaged 32 MPG. When my gas mileage drops, I check my tire pressure and they are usually down to about 30. Therefore, I realize how important it is to keep them at proper psi if you want good gas mileage. Of course, driving style plays a major role also.

Follow the recommended rating in the car manual and not the rating on the tire. The tire manufacture applies the psi on the tire to indicate the max pressure the tire can handle at it's max loading.

Posted: December 30th, 2005, 5:32 pm
by MEXTHREE
Pressure??

Just check the side driver door panel or ur car manuel it should state the recommended tire pressure and if it dont just stay under the max psi which is on ur tire itself it should state it.

In winter i set my psi 8-9 psi under the max which is labled on the tire i got the mich x-ice for winter 15 inch it says 40 psi i think, so i set it to 32 psi , it might be bumpy if u dont like a bumpy ride go less and i also called a auto shop and mazda dealership they say 29-32 psi is ok in winter (i am in a cold cold part of canada)
winters my differ from state to state, province to provice or country to country) as in recommended psi for your tire

in summer i set my 16 inch psi to 26-28 psi

summer tire pressure = check car panel or car manuel
winter tire pressure = read above,

i guess imports dont got a recommended tire pressure cuz they come from a land where snow is never heard of lol

"snow? what is snow???"


Hope this helps :)

Posted: December 30th, 2005, 6:34 pm
by jschrauwen
One should always carry a GOOD tire pressure gauge in their car at alll times.
Mex, when you have time, give my 3psi rule a try. Takes the guess work out of it all of the time.
Joe, try it with your pancakes too ....LOL