[caramihn]

Hi all,

I have recently purchased an '89 Deville in great condition. It pulls a bit to the right, so I wanted to make sure all the tires are at their correct pressures. The sticker on the door is missing, can anyone kindly tell me what the recommended pressures are for all four wheels?

 

[Discount Tire]

The O.E. tire pressure for the O.E. tires for your 89 would be 30 PSI.

What size tires are on the car? If you're running something other than O.E. sizing then the pressure may need to be adjusted depending on the load index and the construction of the tire.

 

[91FleetwoodCoupe]

They call for 30 but being a big heavy car I do 35.

 

[caramihn]

What size tires are on the car?

215/70R15, I believe these are OE. Thank you for your quick reply

 

[Discount Tire]

I show 205/70R-15 as O.E. sizing - which brand and tire model is installed on the vehicle?

 

[basscatt]

They call for 30 but being a big heavy car I do 35.

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you gain nothing by over inflating the tires -
you MIGHT actually shorten the life of the tires -
not to mention giving a harsher ride -

 

[Byrdman]

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you gain nothing by over inflating the tires -
you MIGHT actually shorten the life of the tires -
not to mention giving a harsher ride -

yup. you'll have premature wear in the middle of the tread.

 

[caramihn]

I show 205/70R-15 as O.E. sizing - which brand and tire model is installed on the vehicle?

You're right, I guess the previous owner put slightly wider tires. They're Yoko's in the front and Goodyear's in the back. I have them at 32 psi currently

 

[Submariner409]

Tire tread wear diagnosis..................

The manufacturer's recommended cold inflation pressures - on the driver's door sticker and/or owner's manual - are developed for THAT car/tire OEM specification. Increasing pressure by more than 1 - 2 psi only contributes to accelerated wear - it has NO effect on a "heavy" car or weight carrying abilities, but contributes to a harsher ride and increases suspension over-reaction to road surface faults.

 

[91FleetwoodCoupe]

========================
you gain nothing by over inflating the tires -
you MIGHT actually shorten the life of the tires -
not to mention giving a harsher ride -

On my Pontiac I had found the tires to look far too underinflated at 30 and the tire shop agreed so went to 35 at their suggestion and had no issue in years. Just did the same with the Cadillac since it's even heavier.

 

[basscatt]

On my Pontiac I had found the tires to look far too underinflated at 30 and the tire shop agreed so went to 35 at their suggestion and had no issue in years. Just did the same with the Cadillac since it's even heavier.

=======================
it's your car and your tires so do whatever you want -

I'm simply providing the FACTS -
1) 30 psi is the correct inflation for the stock size tire -
2) there is absolutely no benefit to over inflating the tires by 5psi -
3) overinflated tires will give LESS traction in ALL circumstances because of a smaller contact patch -
4) over inflated tires WILL wear out the center of the tread faster - thus shortening the tire life -

by the way -
the tire shop only "agreed with you" because it wasn't worth their time to discuss it further -
you want 35 - go ahead - put in 35 -

true story -
I had a customer - old guy - that came in twice every year to change the summer air to winter air -
ONCE - I tried to explain that there was no difference between "summer" air and "winter" air -
after that ONE TIME - I didn't bother - HE wanted the damn air changed - so I changed it - HE was happy -

 

[Submariner409]

"look far too underinflated" - radial tires WILL always look underinflated. They have very flexible sidewalls compared to bias-ply tires.

Vehicle weight has exactly nothing to do with changing recommended tire inflation pressures for that vehicle - and vehicle weight is one of the factors used when the manufacturer originally recommends a cold inflation pressure and tire load carry range. (Yes, tires are fitted to a specific load carrying ability range)

When all else fails, read the directions - get into www.tirerack.com and study the white papers.