Whatis the proper pressure for 17" tires

[Davebert]

I just got an 06 GT last week. It came with a new set of BFGoodrich g-Force super sport. What is the proper tire pressure for it? Do I use what is marked on the side of the tire (max) or it is best to use lower pressure.

Thanks.

[AwaKeN]

It's 32 or 34 PSI, it's written on the inside of the driver door (sticker) on the pillar between the 2 doors.

[bulwnkl]

Do NOT use what is marked on the side of the tire for daily driving unless you have your 5 loaded to max GVW all the time. That pressure is the MAXIMUM pressure the tire is rated to contain safely, and is the pressure at which the tire will safely carry its maximum rated load.

The pressure on the placard/sticker in the door/doorjamb is what Mazda says is the best compromise of fuel economy, ride and handling, tire wear, and noise for the vehicle. You can adjust from there if you prefer greater emphasis on some particular aspect of that trade-off. However, be careful of going much lower than what is on the placard. Too-low (incorrect) tire pressure is the cause of the Ford Explorer rollover issue that was erroneously blamed on a brand of tires a few years ago.

[AwaKeN]

You say DO NOT USE this PSI but don't go higher or too low ... If Mazda recommend this pressure why not just put that pressure in your tires ?!!?!?

[93mx6]

just look at what the maximum tire pressure is on the actual tire should be 44 psi max, but id say 33 is good amount to run.

[mazdaspeedster3]

I run 34 in the front (engine weight) and 32 in the rear pretty much all year round with ZERO issues on both my Mazdaspeed3 and my Mazda5.

[AwaKeN]

I run 34 / 34 with no issues ...

[mazdadude]

Always use the VEHICLE manufacturer suggested PSI. If you want to experiment, I would stay within 10% + or - of the reccomended PSI.

Of course this only applies to the OE Tire size, and OE Tire Load rating.


The TIRE manufacturers MAX PSI rating is not what you use in the tire.

It is kind of like saying your stomach will hold 4 cheeseburgers max, but you will be safer, and have a more comfortable ride with just one cheeseburger. :p

I run 34 psi in mine

[morethan5]

40 psi in the back
42 psi in the front
has worked well for me (2008, ~21,000 miles).

Based on the wear to date, if I were to take the tires to the 2/32nds limit, I'd get about 34,000 miles out of them.

At these pressures, center-wear equals edge-wear for me.

[AwaKeN]

Always use the VEHICLE manufacturer suggested PSI. If you want to experiment, I would stay within 10% + or - of the reccomended PSI.

Of course this only applies to the OE Tire size, and OE Tire Load rating.


The TIRE manufacturers MAX PSI rating is not what you use in the tire.

It is kind of like saying your stomach will hold 4 cheeseburgers max, but you will be safer, and have a more comfortable ride with just one cheeseburger. :p

I run 34 psi in mine


X2 Thanks for your support (yippy)

[skyhawk]

mazda5 2006. 34psi. as per the sticker in the pillar.

I think over inflation will cause the center of the typical tire to wear faster.
and with mazda5's rear camber, the wear will be on the inner side.

[morethan5]

I think over inflation will cause the center of the typical tire to wear faster.
and with mazda5's rear camber, the wear will be on the inner side.

I agree. Over inflation will cause accelerated wear to the center of the tires. By that definition the 42/40 pressures that I'm running are pretty close to the correct -- at least for my driving, as my tires are uniformly worn.

For passenger vehicles, the manufacturer selects a pressure that optimizes competing requirements -- load carrying ability, handling, stability, rolling resistance (MPG), ride quality, wear, etc. The optimization changes based on the relative importance given to each criteria. If tire pressures were set to 40+ psi on dealer demonstrators, there would be suspension complaints, and fewer vehicles sold.

I adjusted the pressure to get uniform wear. Improved handling and gas mileage came at the cost of ride compliance.

[mrbwa1]

For the record, the "Proper" inflation is on the door placard. IT is the pressure that the vehicle was designed to use for best compromise of safety, ride, handling, etc.

That said, I like to run a little higher, as I have seen real, but small MPG gains (1-2 MPG if driven carefully) at 38 PSI in the OEM Toyos. On winter tires, the Owner's manual states to add 3.something (3.2 I think) lbs to the tires. I run the 205/55-16 Dunlop Wintersport 3Ds at 41 PSI (3 more than the 38 I run in the OEMs).

The ride does stiffen up with more pressure though. Realistically, if you are testing pressure cold, you can inflate to the sidewall max for max MPG benefit without much danger of tire issues. Heck, Our 5 came from the dealer with 51PSI in 1 tire and the max is only in the 40s! Yes I did correct it. No I would never go over the sidewall max cold.

[stillageek]

I'm running 42/40. I haven't had problems. I have them higher than normal as I don't drive much. My car sits 3-4 days between use. I drive 600 miles a month and have had a tracked average of 27 MPG over the last 6 months. Most trips are 10-15 miles in the city with the longest EVER trip of 80 miles on the highway. The MPG has exceeded my expectations.

[bulwnkl]

You say DO NOT USE this PSI but don't go higher or too low ... If Mazda recommend this pressure why not just put that pressure in your tires ?!!?!?

Were you talking to me? I didn't say to not go higher nor lower. I said to go by the door placard rather than the number on the tire. I also warned that too-low tire pressure is a major cause of crashes.

[huxlee]

You say DO NOT USE this PSI but don't go higher or too low ... If Mazda recommend this pressure why not just put that pressure in your tires ?!!?!?

my 09 m5 sport (UK) has dunlop SP2050 205/50/17 v93
Mazda state full load tire pressure 41 psi rear
tires state do not inflate above 40 psi

why do Mazda fit tyres unsuitable for there vehicles?

[Franzy]

The door placard is based on the style of tire that the mfg buys for that car. It is NOT always right. The rule of thumb for your tires (with typical compressed air) is look at the max pressure and back off 5-8% during the colder months and 6-10% during the summer months. This depends on the volume of air, humidity, and a whole slew of other factors.

I bought 1 pair of tires that had 45 as max PSI and a different set that had 42 as the max PSI. You had to back off pressure differently for each group.

Out here in TX I use 5% off in winter and 7or8% off in summer. The tires wear evenly with no problem.

[hagow_boy]

40 PSI on all 4 tires in the last few months. Before this I had 42 PSI on all 4 since I got the car in March 2007. 40000 Kms on the original Toyo 205-50-17's and no uneven tire wear. Have been getting the tires regularly rotated with every few oil changes. I find that at 35 PSI, I was getting tire squeeling accelerating off the line and when making tight turns. At 40 PSI, I don't get any noise or sidewall rubbbing.

[BT Automotive]

I go just under max pressure on any low profile tires.

[Robotaz]

Actually, the pressure rating on the door is what the suspension was designed to ride on with the tire stated on the same sticker. If you want the car to ride the way it was designed, use the stated tire size, speed rating, and tire pressure. The brand of tire doesn't matter at all. Obviously you can run up to the max pressure stated on the tire also, but it will most likely be very stiff.

[skyhawk]

I set mine to the recommended 34 psi.

The toyo is also weird. The inside was wearing fast when it was new.. then as the rubber got worn down to the 'alignment marks' (not yet the 'replace me' mark), the wear started to appear even. So maybe it is a rubber quality issue.
like the outer layer is softer.. Or maybe the rubber hardened with time.

[SGT_OKINAWA]

(attn)


40 PSI on all 4 tires in the last few months. Before this I had 42 PSI on all 4 since I got the car in March 2007. 40000 Kms on the original Toyo 205-50-17's and no uneven tire wear. Have been getting the tires regularly rotated with every few oil changes. I find that at 35 PSI, I was getting tire squeeling accelerating off the line and when making tight turns. At 40 PSI, I don't get any noise or sidewall rubbbing.

I could go on some long rant about this... but I'll just say, good luck, 42 PSI IMO is to high.


I go just under max pressure on any low profile tires.

That is a miss conception in most circles, NORMAL psi is still used, those LOW PROFILE tires are MADE to be used just like the normal 'stock' tires, (that is why they cost so darn much) I'd dile it down to 36 PSI if I was you, or go the recommended 34.

Peace!(rei)

[TheMAN]

European/General Market service manual states:
220kPa for normal use with stock 17" tire size
but for full load, 240kPa in the front and 280kPa in the rear

this is done because there is less sidewall in the tires and more air is required to maintain sidewall rigidity (if the sidewall collapses, sidewall damage will occur as well as poor traction from the tires... it's like driving an empty vehicle with 150kPa of air! ford exploder anyone?)


otherwise for normal use, I agree that there's no reason to go higher than 220kPa as the correct tire size and load rating is designed to be run on this vehicle at that pressure... HOWEVER, when you upgrade to different rims, wider/lower profile tires, it is advisable to bump up the pressure 10-20kPa more in order to keep the sidewalls stiff... like I said, sidewall deformation essentially means driving around with flat tires... when you hit a nasty pothole, your tire gets bubbled (radial belts broke) or worst yet, break/bend the rim

on my protege, stock pressure is 32psi (220kPa), but now that I have mazdaspeed rims on there with wider and lower profile tires, I have to run 35psi (240kPa) or risk breaking the tire/rim