: New recommended tire pressures for 2012



guyflyguy
09-16-2011, 07:12 PM
My 2011 Volt has a recommended tire pressure of 35 psi. I just noticed that my 2012 has a recommendation of 38 psi. Whats correct - why the change?
2011-02499 White "EPOWER"
2012-00444 Red "GO EV"

leeG
09-16-2011, 07:55 PM
Whatever is on the driver's door Tire and Loading Information Label is correct for that car.

I suspect more psi means more mpg.

tangentlin
09-16-2011, 11:32 PM
I read in the forum that the tires are supposed to go as high as 51psi. I have mine at 45psi, I cannot tell how much further I could go with the tire pressure.

MTN Ranger
09-16-2011, 11:32 PM
The 2012 demo I drove had 35 all around. I assumed it was the same as last year.

stuart
09-16-2011, 11:34 PM
My 2011 Volt has a recommended tire pressure of 35 psi. I just noticed that my 2012 has a recommendation of 38 psi. Whats correct - why the change?
2011-02499 White "EPOWER"
2012-00444 Red "GO EV"

Are the tires identical across model years? If so that would finally answer the question about whether to run the 2011's at higher PSI than originally recommended.
Thanks
STuart #2209

SharkVolt
09-17-2011, 12:31 AM
It might be that GM, after extended mileage on these tires has found that 38 pounds gives more uniform tire wear, and also that higher pressures result in more cornering power from the front tires without so much squealing. I have found that as much as 45 pounds gives noticeably better cornering performance, but does give a little harsher ride over bumps, etc.

scottf200
09-17-2011, 01:24 AM
It might be that GM, after extended mileage on these tires has found that 38 pounds gives more uniform tire wear, and also that higher pressures result in more cornering power from the front tires without so much squealing. I have found that as much as 45 pounds gives noticeably better cornering performance, but does give a little harsher ride over bumps, etc.

Interesting short article here we have posted before:

Driving Under Pressure - Sgt. Dave Storton - Officer.com - December 21, 2005
http://www.cleanmpg.com/forums/showthread.php?t=11652

I put 40 lbs in my Volt tires. Sidewalls I think do say 51lbs.

Bob_Livonia
09-17-2011, 07:51 AM
I would go with the the pressure specified by the sticker on the vehicle; there is considerable engineering work that goes into it. (Years ago, Ford got caught having too low a pressure in their Explorer for a soft ride. Trouble was people would let the pressure go down even further by not checking, before the mandated tire pressure sensors, and the tires would heat up and blow and vehicles would sometimes disastrously flip - sure most of you have heard of that).

That being said, the chief engineer of the Volt told me at the Woodward drive that he has set his tire pressure at 38; he said as long as you don't plan to do a lot of hard cornering, 38 should be fine. If 38 is good enough for the chief engineer, it's good enough for me.

I wouldn't go higher, like anywhere near 51. If there were no negatives, GM would just go with the max rating pressure and be done with it.

Jim Fallston Md.
09-17-2011, 08:25 AM
I was told that it is safe to put upto 4 psi less than the max tire pressure rating on the sidewall. ie 51 psi on sidewall , 47 psi will be a safe tire pressure. This is for any car tire.

Rusty
09-17-2011, 03:35 PM
If there were no negatives, GM would just go with the max rating pressure and be done with it.

But there are negatives for going with higher pressure. It produces a harsher ride. GM has to strike a balance between better gas mileage and a smoother ride. For the '11 they apparently went for the smoothest ride they could get. For the '12 they apparently decided the ride was smooth enough at 38 and the mileage was better.

Some Volt drivers are willing to go with an even "rougher" ride (in quotes, 'cause at least at 40 it's still an incredibly smooth car) in exchange for even better mileage. But while 40 (2 PSI over) is fine, I'm thinking 50 is a bit much!

hermperez
09-17-2011, 04:14 PM
Radial tires are vastly VASTLY underrated when it comes to max pressure.. you can easily go double the max rating printed on the sidewall without any wear or explosion issues.. but the ride will get quite harsh, you will feel every pebble on the road. You can also use tire pressures to change how your car oversteers/understeers if you want to.

The same is not true of bias-ply tires as used in high load trucks and pickups, too much pressure and you will get bad wear patterns, but you still need those tires for their high load capacity.

c6vette
09-17-2011, 05:27 PM
My 2011 Cruze calls for 35 lbs while my 2012 Volt calls for 38 psi- Tires are the same-You would think the Volt which weights more would have the higher pressure--just the opposite.
Just thinking, I wonder if the spare tire from the Cruze would fit anywhere on the Volt. Have not got around to trying the switch.
Corrected error!!!

scottf200
09-17-2011, 06:02 PM
My 2011 Cruze calls for 38 lbs while my 2012 Volt calls for 35 psi- Tires are idendical-You would think the Volt which weights more would have the higher pressure--just the opposite.
Just thinking, I wonder if the spare tire from the Cruze would fit anywhere on the Volt. Have not got around to trying the switch.

Tire pressure changes a lot with outdoor temp and driving warming up the tire temp. I put 40lbs in a couple weeks ago and with the cooler weather they are showing like 36 now.

Quite an interesting situation you have with '11 Cruze and '12 Volt. You should start a thread on your reasonings.

Re: Spares:
This thread should go in the FAQ
Spare-tire-solution
http://gm-volt.com/forum/showthread.php?8263-Spare-tire-solution

RDO CA
09-17-2011, 08:02 PM
My 2011 Cruze calls for 38 lbs while my 2012 Volt calls for 35 psi- Tires are idendical-You would think the Volt which weights more would have the higher pressure--just the opposite.
Just thinking, I wonder if the spare tire from the Cruze would fit anywhere on the Volt. Have not got around to trying the switch.

who is correct here?--you say 2012 is 35 and the the first poster says 38

Plrands
09-17-2011, 08:53 PM
Just checked the door sticker on my 2012 and it list 38 psi (and so does the manual).

c6vette
09-18-2011, 07:28 AM
who is correct here?--you say 2012 is 35 and the the first poster says 38
Sticker on the 2012 Volt says 38. Sorry for the error.

Matt979
09-18-2011, 12:09 PM
So as a newbie, does that mean I should inflate mine more as they say 35 or 36 on the screen?

Slapshot28
09-18-2011, 12:18 PM
So as a newbie, does that mean I should inflate mine more as they say 35 or 36 on the screen?

The standard answer is GM knows best, so inflate to whatever is marked inside the door.

That said, a number of people suggest that a bit more pressure will provide a firmer feel, and may enhance mileage. Also, note that tire pressure will go up after driving, especially at highway speeds. But no worries, the tires can handle this easily. Suggestions of increased tire wear at higher pressure are not substantiated in my view.

I come from driving sports cars, and I prefer the firm ride (and driving in Low, and the low air dam!). So, even though the door says 35 psi, my Volt tires are at 41 psig when cold (i.e., after sitting in the garage all night).

Chris
Volt #541

Bob_Livonia
09-19-2011, 08:30 AM
I was told that it is safe to put upto 4 psi less than the max tire pressure rating on the sidewall. ie 51 psi on sidewall , 47 psi will be a safe tire pressure. This is for any car tire.
Gives a new meaning to the Chevy "like a rock". You are asking for blowouts / cord damage (with no spare), wear in the center and poor cornering if you go anywhere near the 47 PSI you are advocating.

DonC
09-19-2011, 11:57 AM
Getting back to the difference between MY 2011 and MY 2012, it seems that GM has changed it's mind and that the new recommendation is 38 psi. The tires are the same right? Or is there something I'm missing?

maynard
09-19-2011, 07:00 PM
We keep ours at 46 psi. There was a thread here some time back that said there are no adverse affects up to the 51 psi on the sidewall and that that number is 20% below the real max. Tire wear is not affected. Economy is improved.

c6vette
09-20-2011, 03:54 PM
Just tried to put the donut spare from my 2011 Cruze on the 2012 Volt--no good. Pattern is slightly different. You would think that the exact same size tire would have the same bolt pattern. Guess I'll take the Cruze on the long trips or try my luck with the Volt inflator/gunk crap!

RDO CA
09-20-2011, 09:35 PM
We keep ours at 46 psi. There was a thread here some time back that said there are no adverse affects up to the 51 psi on the sidewall and that that number is 20% below the real max. Tire wear is not affected. Economy is improved.

That is not correct that there is no adverse effects. It is also correct that it is safe to increase the pressure. Do what you want but the tire companies along with GM have suggested a pressure that will do several things correctly. 1-Give you a good ride and not be to harsh. This is up to you what ride you like. 2- Give you proper handling. 3-Give you good tire wear. If you put too much air in the tire it will wear in the center and not give the life as it will with proper inflation that gives a even patch across the tread face. You will get a marginal increase in milage but at what cost in ride and wear. The tire should only be checked and inflated cold as that is how they set the pressure and it is good to check in the morning or before you drive any and it has set long enough to fully cool. If you set the pressure at the uper limits and drive on the highway fast the pressure will increase quite a bit. I will set mine at about 1-2 lbs over the recomended as tires can slowly loose pressure and if you dont check often can run low. The tire sensors are not exact so it is only a close estimate. I see the one in the car differs some from my gauge and the phone app differs some also. If the new tires are exactly the same as last year GM probably reevaluated the recommended and I woud go to the 38 number and maybe 1-2 more.
Roy #272

scottf200
09-20-2011, 11:26 PM
Just tried to put the donut spare from my 2011 Cruze on the 2012 Volt--no good. Pattern is slightly different. You would think that the exact same size tire would have the same bolt pattern. Guess I'll take the Cruze on the long trips or try my luck with the Volt inflator/gunk crap!

In another thread I pointed you to the post on all this and the hole pattern and what vehicles had it.