robwlf
Well-Known Member
im still having good reaction and grip running 32 psi cold.. they heat up to about 34 or 35 on a 90 degree day .. highway they stay pretty much 34 ..so ill stick with that
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Buy a tread depth gauge, check your tire tread depth regularly across the width and adjust pressure accordingly.
275/35/20 F=30 psi, 305/35/20 R=27psi seem to be the normal setting for these tires on my Mustang GT. G-Force comp-2 A/S BF Goodrich.
I will adjust the psi, up or down, depending on tread depth wear across the width of the tire. I have gone as low as 29psi on the fronts and 26psi on the rears to get the tread depth to equalize across the width.
These tires have 10k miles on them and the tread depth across the width of the tire are within .5mm of each other.
Also by doing this you can tell quickly if your alignment is correct/incorrect.
This seems to work for me, I'm no expert.
Seems to me I remember reading on this board somewhere that the factory recommended tire pressure for the 20 inch option was 35.
I don't say its too high for everything but as i wrote earlier, Ford's only worry is to provide a car that ticks the boxes for gas mileage/exhaust limits and will of course have to compensate for any non-standard spec car by inflating the tires more. No manufacturer gives tire specs for best grip / least wear. Today, emissions are everything and running on stock spec will many times give premature tire wear, but that's not the manufacturers problem, it's the customers when he realizes that the good gas mileage comes at a cost.Here ya go: https://www.mustang6g.com/forums/threads/tire-pressure-for-conti-dws-06-20.98239/#post-2151239
If factory recommends it, I doubt it's too high.
I run my Cont DW06 275/35/20 at 35 cold. I can tell when it drops below 33 because the car feels squirrelly. Best I can tell tread wear is fine.
Maybe the calculator assumes equal aspect ratio. If aspect ratio is smaller, more PSI would be needed to provide equal load bearing.
According to tiresize.com it seems you have to compare oem tire size, load rating, and psi from on the door jam, with the new tire size and load rating. The tool on their site spits out the calculated psi you should be running to come as close as possible to supporting the vehicle's weight load. I punched in the oem numbers for the 19s @ 32psi:Hi,
Have now had my new Project 6gr Sevens 20x11 + 20x10 lying around for more than a month and the new set of Pirelli Zeros too. Have been waiting for a set of TPMS that never showed up, and will finally get a set so I can mount the wheels so the next question is: Which tire pressure should I have?
New tires are 275/35R20 (102Y) front and 305/35R20 (104Y) rear.
Stock tires have a load index of 96Y up front and 101Y on the rear.
According to a standard table, using 32 PSI on both rear and front on the stock tires, it should translate to 26 PSI on the new front tires (1415 lbs) and 28-29 PSI (1647 lbs) on the rear tires.
Am I correct?
Hi,
Have now had my new Project 6gr Sevens 20x11 + 20x10 lying around for more than a month and the new set of Pirelli Zeros too. Have been waiting for a set of TPMS that never showed up, and will finally get a set so I can mount the wheels so the next question is: Which tire pressure should I have?
New tires are 275/35R20 (102Y) front and 305/35R20 (104Y) rear.
Stock tires have a load index of 96Y up front and 101Y on the rear.
According to a standard table, using 32 PSI on both rear and front on the stock tires, it should translate to 26 PSI on the new front tires (1415 lbs) and 28-29 PSI (1647 lbs) on the rear tires.
Am I correct?
Hi,
Have now had my new Project 6gr Sevens 20x11 + 20x10 lying around for more than a month and the new set of Pirelli Zeros too. Have been waiting for a set of TPMS that never showed up, and will finally get a set so I can mount the wheels so the next question is: Which tire pressure should I have?
New tires are 275/35R20 (102Y) front and 305/35R20 (104Y) rear.
Stock tires have a load index of 96Y up front and 101Y on the rear.
According to a standard table, using 32 PSI on both rear and front on the stock tires, it should translate to 26 PSI on the new front tires (1415 lbs) and 28-29 PSI (1647 lbs) on the rear tires.
Am I correct?
I'm still running 32 psi cold and got great grip and handling as well as completely even wear so seems to be the sweet spot.According to tiresize.com it seems you have to compare oem tire size, load rating, and psi from on the door jam, with the new tire size and load rating. The tool on their site spits out the calculated psi you should be running to come as close as possible to supporting the vehicle's weight load. I punched in the oem numbers for the 19s @ 32psi:
OEM Size (255/40R19 XL) Load Capacity: 1418 lbs. @ 32 psi.
New Size (275/35R20 XL) Load Capacity: 1431 lbs. @ 30 psi.
Punched in on tiresize.com here are the scientifically correct psi's to run:
Front OEM Size (255/40R19 XL) Load Capacity: 1418 lbs. @ 32 psi. New Size (275/35R20 XL) Load Capacity: 1431 lbs. @ 30 psi.
Rear OEM Size (275/40R19 SL) Load Capacity: 1647 lbs. @ 32 psi. New Size (305/35R20 SL) Load Capacity: 1660 lbs. @ 29 psi.
My setup is Nitto 555 G2's sizes:
F 275/30/20
R 285/30/20
I bought the car this way and only recently dawned on me that these tires may take a different psi than the oem sizes. I punched my numbers in and got
F psi - 36
R psi - 41
Those numbers seemed too high to me so I filled F32/R34, looks good, feels good, only more miles will tell me the tread's wear pattern, and if this tiresize calculator is real-world-helpful.
Meantime hope this tiresize.com tool is helpful, cheers
Holy haha. Fill your tires to 32 PSI, or whatever euro specs call for and call it a day. As another poster stated, this ain't rocket science. But if you wanna turn it into rocket science continue on. I run 32 psi on my fronts (245/45/R19) and 32 psi on my rears (325/30/R19) have have noticed ZERO unusual wear.Yeah that's a great way of ruining a perfect set of tires... Thanks for the tip - not.
Do you fill all your tires on all your vehicles with 32 psi? Why not fill them to 40 PSI and check the thread wear?
Good for you - no-one asked.Holy haha. Fill your tires to 32 PSI, or whatever euro specs call for and call it a day. As another poster stated, this ain't rocket science. But if you wanna turn it into rocket science continue on. I run 32 psi on my fronts (245/45/R19) and 32 psi on my rears (325/30/R19) have have noticed ZERO unusual wear.
Yeah, you asked. Must have different air in Sweden eh ?Good for you - no-one asked.