Question: C-5 tire pressures?

[killain]

What kind of tire pressures do you maintain in your C-5? I have a 2003 with the Goodyear EMT runflats and the tire pressure monitors. The door sticker says 30 PSI cold and 34 hot. i tend to go just a tad higher, 31 cold and 35 hot. I somehow think that with gas prices as high as their are, running a little higher pressure gets me a slightly better MPG. must work cause i do 19 MPG around town and 29 or 30 MPG on the highway. I was just wondering what you folks think? It real hard to get the tire pressures all the same with the tire sensors, they almost never match up with what the pocket tire pressure gauge I use?

 

[caseyk]

What kind of tire pressures do you maintain in your C-5? I have a 2003 with the Goodyear EMT runflats and the tire pressure monitors. The door sticker says 30 PSI cold and 34 hot. i tend to go just a tad higher, 31 cold and 35 hot. I somehow think that with gas prices as high as their are, running a little higher pressure gets me a slightly better MPG. must work cause i do 19 MPG around town and 29 or 30 MPG on the highway. I was just wondering what you folks think? It real hard to get the tire pressures all the same with the tire sensors, they almost never match up with what the pocket tire pressure gauge I use?

I have been having problems with my tire pressures as well.I have KUMHO run flat tires that say the max press. is 51 lbs.I run 40lbs in all 4 tires,but i used to run them all at 32lbs.I just got back from Florida,and I kept getting a message saying my right rear tire had low pressure,I checked it with my pocket gauge and it read 41 lbs.,so for the sake of arguement I added a little air to the right rear tire and once I was going down the road,it tells me I still have low pressure in my right rear and then I started getting another message saying my left rear had high pressure in it! I didn't even touch the left rear tire :bash.Those sensors drive me nuts,I can never get both rear tires satisfied where they won't trip a message on the DIC. I don't know weather to trust the pocket gauge or the car! :confused My car does need a tune up,but I was getting 25.4 mpg on the highway. I did find out recently that the tire sensors run on small batteries,so I may need to have them changed,it is really aggravating to have those messages flashing in my face everytime I drive it. ad

 

[Tuna]

I use the placard numbers on my cars (30 cold) and I get about the same mileage.

I think the run-flat's stiffer side wall makes the tire pressure difference and gas mileage less of a factor.

Don't even think about trying to run them at the 'max' pressure shown on the side of the tire.

 

[killain]

I have been having problems with my tire pressures as well.I have KUMHO run flat tires that say the max press. is 51 lbs.I run 40lbs in all 4 tires,but i used to run them all at 32lbs.I just got back from Florida,and I kept getting a message saying my right rear tire had low pressure,I checked it with my pocket gauge and it read 41 lbs.,so for the sake of arguement I added a little air to the right rear tire and once I was going down the road,it tells me I still have low pressure in my right rear and then I started getting another message saying my left rear had high pressure in it! I didn't even touch the left rear tire :bash.Those sensors drive me nuts,I can never get both rear tires satisfied where they won't trip a message on the DIC. I don't know weather to trust the pocket gauge or the car! :confused My car does need a tune up,but I was getting 25.4 mpg on the highway. I did find out recently that the tire sensors run on small batteries,so I may need to have them changed,it is really aggravating to have those messages flashing in my face everytime I drive it. ad

I'm not sure about Kumho runflats, but i assume their the same size as the original tires, so I don't understand why your running such high tire pressures? I do know that if your running higher than recommended( Like six or seven pounds or more over the recommended in the owners manual) that will throw off your tire pressure sensors. I had to replace one a couple of months ago Because it wouldn't register the right tire pressure. Likewise I'm not sure the batteries can be replaced. Plus depending on your vettes age they might be worn out. But I like you have a Heck of a time trying to get the sensors and tire pressure to match!

 

[Blu Cah]

I have the KUMHO ECSTA (XRP) run flats on my y2k with 30 psi of pressure and they run just fine. Last road trip I got 28.5 mpg. While driving on the highway, the DIC shows 33 psi on each tire.

 

[jrose7004]

I run 30 psi cold all the time.

 

[U.P. John]

Me too.

I have the originals. Once I inflated them up to 40# in error, and the service manager from the local Chevy dealer came over and told me to knock it off. How did he know???

I know when to give in...

 

[caseyk]

I'm not sure about Kumho runflats, but i assume their the same size as the original tires, so I don't understand why your running such high tire pressures? I do know that if your running higher than recommended( Like six or seven pounds or more over the recommended in the owners manual) that will throw off your tire pressure sensors. I had to replace one a couple of months ago Because it wouldn't register the right tire pressure. Likewise I'm not sure the batteries can be replaced. Plus depending on your vettes age they might be worn out. But I like you have a Heck of a time trying to get the sensors and tire pressure to match!

I think I will let some air out of my tires and get them all to 30 lbs. cold and give that a try,it makes sense what you said about having higher tire pressure than the owner's manual recommends.My tires are indeed the stock sizes that came on the car,so the higher pressures are probably freaking out my tire sensors. :cool

 

[killain]

I think I will let some air out of my tires and get them all to 30 lbs. cold and give that a try,it makes sense what you said about having higher tire pressure than the owner's manual recommends.My tires are indeed the stock sizes that came on the car,so the higher pressures are probably freaking out my tire sensors. :cool

Also i think it says in the owners manual that you need to run the tires around for fifteen minutes so that the PCM can upload the new tire pressure info!

 

[DDLS3]

I have an 02 coupe and I'm on my second set of tires. I run 30 psi cold and get great milage and good tire wear. The pcm immediately recognizes a tire presure change as soon as the transmitter (tire pressure monitor) and the receiver communicate upon starting the engine after a change. If your pressure monitor is starting to read lower than actual pressure then your sensor battery is fading and you will be needing to replace a sensor soon. Mine took about six months to fade out and eventually die. I use a digital tire gauge and find that the sensors are always very close. My digital gauge recalibrates after every use so it remains fairly accurate.

Dale

 

[Jistari]

Pulled into my Shell station the other day (not with the C5, but the honda needed air) and saw they had a newer digital type of air unit.

What was nice is that you set the pressure on the unit and put the hose on the valve stem, it adds air up to the pressure you set, but also lets air out if the tire is over the pressure you set

Didnt have a lot of problems getting all corners to be within a pound of each other using a regulat air hose and a hand held slide guage before, but this thing is gonna make it "plug and play".

And btw, I run 30 cold.

 

[PreacherNutshot]

I have been having problems with my tire pressures as well.I have KUMHO run flat tires that say the max press. is 51 lbs.I run 40lbs in all 4 tires,but i used to run them all at 32lbs.I just got back from Florida,and I kept getting a message saying my right rear tire had low pressure,I checked it with my pocket gauge and it read 41 lbs.,so for the sake of arguement I added a little air to the right rear tire and once I was going down the road,it tells me I still have low pressure in my right rear and then I started getting another message saying my left rear had high pressure in it! I didn't even touch the left rear tire :bash.Those sensors drive me nuts,I can never get both rear tires satisfied where they won't trip a message on the DIC. I don't know weather to trust the pocket gauge or the car! :confused My car does need a tune up,but I was getting 25.4 mpg on the highway. I did find out recently that the tire sensors run on small batteries,so I may need to have them changed,it is really aggravating to have those messages flashing in my face everytime I drive it. ad

I'd definitely drop your pressure, or you're going to get uneven tire wear. I also think you need to reset you sensors. If you put air in the right rear tire and the left rear over inflation warning comes up, I'm guessing your TPS's got switched between sides.

 

[65-to-00]

Kuhmo run flats and I run a bit over 34 (hot).

On a long trip Maine to NJ, I was getting a solid 29.9 to 31 something the whole trip. Did a double check with the pencil and pad and it was right on. Got great numbers up and back.

Granted, the trip was done at "optimum" times to avoid places like Hartford CT, at traffic time and such.

That tall 6'th gear had to help! All speeds were an average of about 74 mph.

 

[killain]

Kuhmo run flats and I run a bit over 34 (hot).

On a long trip Maine to NJ, I was getting a solid 29.9 to 31 something the whole trip. Did a double check with the pencil and pad and it was right on. Got great numbers up and back.

Granted, the trip was done at "optimum" times to avoid places like Hartford CT, at traffic time and such.

That tall 6'th gear had to help! All speeds were an average of about 74 mph.

that' great news, and i think we all try to travel at optimum times. Right here where I live, Rt.95 runs right along side Essington and whenever i seew the miles of backed up traffic headed south at 3:45 I can't help of thinking of all that wasted gas!

 

[bwing]

Here's something to throw a wrench in your gears. What are the effects of putting nitrogen to inflate your tires? I've heard that if you put 32 psi it's a constant 32 psi regardless how far you've driven. Tire heat will not affect the pressure. All of the cars I've seen with green valve stem caps are inflated with nitrogen.

 

[Patrick]

Here's something to throw a wrench in your gears. What are the effects of putting nitrogen to inflate your tires? I've heard that if you put 32 psi it's a constant 32 psi regardless how far you've driven. Tire heat will not affect the pressure. All of the cars I've seen with green valve stem caps are inflated with nitrogen.

Bwing,
If you do a search of the forum using "Nitrogen" as your keyword, you'll find there are dozens of threads discussing this subject in each of the generation sub-forums. I found this one in the C5 section:

CLICK

In particular, read down to Tom Bryant's comments- the thread is only 14 posts long, so it isn't a particular long read. Tom, I think, puts the issue of nitrogen in your tires into its proper perspective.


-Patrick

 

[killain]

Here's something to throw a wrench in your gears. What are the effects of putting nitrogen to inflate your tires? I've heard that if you put 32 psi it's a constant 32 psi regardless how far you've driven. Tire heat will not affect the pressure. All of the cars I've seen with green valve stem caps are inflated with nitrogen.

Well, right after getting my 2003 yearly state inspection, i ran over a strip of sharp metal and ruined one of tires, so there's another $500.00 and I've come to the conclusion that it's mathematically impossible to get the four sensors and a reliable tire guage to match each other as far as tire pressure goes. I'm trying to get the DIC and the tire pressure guage to be close and that the tire sensors don't go off for too low or too high tire pressures. I'm just too frustated with the whole tire warning system.

 

[robs817_c5]

Hi Jim,
I run my tires at 30 psi cold all the time. I get good wear & decent mileage. Once at operating temp. they all read 33psi.
robs817_c5

 

[killain]

Hi Jim,
I run my tires at 30 psi cold all the time. I get good wear & decent mileage. Once at operating temp. they all read 33psi.
robs817_c5

Hi Rob, Yeah your right. I have decided to do what the GM tech at my dealership said. Try to get a decent tire pressure gauge and go by that and forget about the sensors and the DIC. For all the power the PCM has, the information it gets is spotty. IE: My tires have 30.5 PSI in them, and the DCI says the tires are low at 29 PSI. Again, the engine temp gauge says the engine temperture is 212 degrees, the DIC says the engine temp is 199 degrees. I suppose as well made as the Corvette is, Electronics are just not up to the task. Thanks for you info.
Jim Ward

 

[Eric]

I ran 30 cold all the time when I had GY EMTs and I run 30 cold all the time now with my non run-flats. Automatic with performance axle and I got the same mpg with and without run-flats.

- Eric