Hi,
I just bought a set of wheels and tires. My car has 205/55/R16 stock and now these are 215/45/17. The tires are Flaken ZE512. I was wondering what the tire pressure should be?
Here is my story. Originally they were at 42 psi filled with nitrogen. The max pressure is 51 psi. On my car it said 30 psi stock. So I brought the pressure down to 34 psi. Should it be higher and how much? Now that they are filled iwht nitrogen, can i just add air if needed?
Thanks
Usually at where I work, Kal-Tire we go buy what the maximum inflation pressure is, and go ten psi below that, so on a tire rated at 50psi max pressure we'll either go 40 or 35psi.
Being that they are nitrogen filled, I don't think you want to add air.
I have heard that the reason shops are switching to nitrogen is because the nitrogen is thicker than air and doesn't leak as quickly as air, even when a tire has no nail holes in it, it will still very slowly leak air because the tire is never perfectly sealed. Nitrogen is thicker and won't escape as easily.
34 should be a good pressure to run, 30 probably wouldn't be bad either, but since you have lower profile tires, a few more pounds wont hurt to make sure you don't wear them on the outside too much.
1983 Camaro Z28
ling427ttvette wrote:Being that they are nitrogen filled, I don't think you want to add air.
I have heard that the reason shops are switching to nitrogen is because the nitrogen is thicker than air and doesn't leak as quickly as air, even when a tire has no nail holes in it, it will still very slowly leak air because the tire is never perfectly sealed. Nitrogen is thicker and won't escape as easily.
34 should be a good pressure to run, 30 probably wouldn't be bad either, but since you have lower profile tires, a few more pounds wont hurt to make sure you don't wear them on the outside too much.
Thanks, I guess I'll leave them at 34 for now. And If I see they are wearing quickly, I'll increase the pressure.
I appreciate your explanation!
Well, if you notice more wear on the middle of the tread than the outside has, then you will need to drop the pressure a few pounds. Probably to about 30 or so. Just take a look at your tread every now and then and if you have any questions, feel free to shoot them my way.
1983 Camaro Z28
whats the reason you went with the 215's? instead of the 225's?
Vincent Morris wrote:whats the reason you went with the 215's? instead of the 225's?
Well I just wanted to keep my speedometer as accurate as possible.
There is a speed difference of 0.3% between the 215/45/17 and the stock 205/55/16.
That's the reason.
The 225's would have been nice though!
ling427ttvette wrote:Well, if you notice more wear on the middle of the tread than the outside has, then you will need to drop the pressure a few pounds. Probably to about 30 or so. Just take a look at your tread every now and then and if you have any questions, feel free to shoot them my way.
I'll leave it at 34 for now, and as you say, if the middle wears too quickly, I'l lower the pressure a little. Thanks for the info!
I rock my 215/35's with 40psi
On 19's I would run 40 psi to save the rims over the tire, but 18's and 17's I would run 35psi. Just check the wear on your tires. If you are wearing just on the middle your psi is to high. If you are wearing on the sides only bring up the psi some. Also if you are wearing on the sides might want to check alinement.
What would be a good pressure for this same tire only a 205/50/15?
why must people spit out BS.
alot of you guys are very knowledgeable about cars, but you guys know nothing about tires.
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If you're using nitrogen, you can put more pressure in cold than with air.
wrong. Nitrogen will fluctuate with friction and temperature do to driving on them, but not as much as air does. where "regular air" will fluctuate about 1 psi for every 2-3* C the temperature changes, it would take more of a temperature variation for it do raise that same 1 PSI with nitrogen. this is to do with the larger molecules of nitrogen and the percentage of purity of nitrogen thats in the tires.
for nitrogen to be effective, there needs to be 97% or better percentage of the air in your tires to be nitrogen. "normal" air is only about 78% nitrogen.
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we go buy what the maximum inflation pressure is, and go ten psi below that, so on a tire rated at 50psi max pressure we'll either go 40 or 35psi.
VERY WRONG.
inflation pressures are very important to tire life, vehicle handling, and fuel economy. pressures set too high can lead to the center of the tire wearing out too quick. pressures set too low can lead to the shoulders wearing out to quick and poor fuel economy. tire pressures being too far off from optimal will lead to poor vehilce handling and can lead to the car operating in an oversteer condition.
the tire pressures that the manufacturer suggest are based on SEVERAL physics caluculations and SEVERAL real life tests. they are not something that should be taken lightly. when replacing tires with the OE recomended size, follow the OE recomended pressures, REGARDLESS OF WHAT THE TIRE SAYS! the only thing you need to look at the tire for in this aspect is to make sure that the pressure that the vehicle manufacturer suggests is not over the maximum tire pressure (example, a van that calls for 36psi like the newest safaris and astros when most of the tires made in that size of 215/70R16 have a max of 35psi).
when you are changing tire size like plus sizing (plus 0, plus 1, plus 2, etc) you need to make sure that you are using the inflation tables. the inflation tables basically take care of all the calulations into acount for you and will give you the pressure you should run.
in response to the original posters question, from what i can remember from the inflation tables i used to use, 34-36 psi is where you want to be for that size. the reason why i gave you that range is because i cant remember the exact pressure it works out to.
for all those that dont agree with me, show me the training that you have to say what you have said. show me what tire manufacturer suggests adjusting pressures the way you guys have said. i dont mean to sound like a smart ass or anything, but its what i used to do for a living. the scary part is when people make suggestions on peoples tire pressures like that and dont realize what they are suggesting or what the consequences can be. peoples lives can be at stake when i tire blows from wrong inflation pressures or a loss of control because the vehicle now oversteers instead of slightly understeering like the manufacturer suggests.
1997 Cavalier Z24 - 16.3 in 1320 and falling...
rkm1989 rkm1989 wrote:What would be a good pressure for this same tire only a 205/50/15?
those shouldnt even be on the car cause they are undersized.
1997 Cavalier Z24 - 16.3 in 1320 and falling...
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whitegoose( RedR-ZedR)
Today 11:50 AM
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rkm1989 rkm1989 wrote:
What would be a good pressure for this same tire only a 205/50/15?
those shouldnt even be on the car cause they are undersized.
Yea, I bought the wheels and tires before I knew anything about cars (of course I thought I did, typical newb behavior
)Lesson learned though. What would you recommend?
205/60R15's would work nice on there. i used to run those on my 98 sedan.
without the inflation tables infront of me i couldnt work out what you would need for the 205/50R15's for tire presure.
1997 Cavalier Z24 - 16.3 in 1320 and falling...
That's ok. Yea I think you're right, the 205/50/15's just look too small, I could like set up a sleeping bag and call it a night on top of my wheel it's so spacious in there
. I'm pretty sure I'm gonna go with the 205/60/15s when I get new tires (which will be soon from the looks of things). Do the 205/60/15's look ok on a non-lowered car? I plan to lower a bit in the future but $$$ isn't exactly permitting at the moment and I don't wanna be stupid about it and buy cheap struts/springs.
