Edmunds dealer partner, Bayway Leasing, is now offering transparent lease deals via these forums. Click here to see the latest vehicles!
Options
Popular New Cars
Popular Used Sedans
Popular Used SUVs
Popular Used Pickup Trucks
Popular Used Hatchbacks
Popular Used Minivans
Popular Used Coupes
Popular Used Wagons
Comments
It's not like filling a tank of gas, the bigger the tank, the more it contains. It's based on pressior.
A smaller tire will optimally have fewer square inches of contact with the road and therefore requires more pounds per square inch in order to support the weight of the car.
tidester, host
SUVs and Smart Shopper
IOW Contact patch in sq in = weight in pounds on the tire divided by the pressure in the tire in psi
Exactly! IOW, pressure = weight ÷ area!
tidester, host
SUVs and Smart Shopper
Sorry, but even though the dimensions work out, this is incorrect. Average contact pressure does not equal inflation pressure.
tidester, host
SUVs and Smart Shopper
Contact area in sq inches is equal to the weight on the tire divided by the pressure in the tire. Not exact as the tire is not a full elastic vessel.
Perhaps these will help
http://auto.howstuffworks.com/tire4.htm
http://www.boeing.com/commercial/airports/faqs/calctirecontactarea.pdf
Your reply appreciated
I don't know about adding pressure due to the car sitting on its tire, as that is the only way I check mine. So if I inflate my tire to 30 psi while off the vehicle and then put it on the vehicle it will be same as, a little greater, or a lot greater pressure? I say same as.
Odd thing happened on my way home tonight..my DIC comes on and says to "Service Tire Pressure Monitor." I check the tires on the DIC and it has stopped registering a read for my LF tire (displays LF -- psi). I stop at a gas station and go through the re-learn steps to relearn each location. The warning goes off and all seems fine. Anyone have an 07 and have this issue?
What I am saying is ".....Contact area in sq inches is equal to the weight on the tire divided by the Average contact pressure - and this is not the same as the inflation pressure......."
This may seem like a trivial point, but it can lead to some erroneous conclusions if you use the area of the contact patch for further calculations as one of your links suggest.
Is it a good estimate? In the absence of any other types of data, you have to use what you have available. But I have seen this be off by 50%.
BTW, Boeing seems to be referring to bias ply tires which behave differently than radial tires. Those belts really change the way the tire reacts to load.
".....I say same as....." Sorry, did that and the front end of a 2000 Buick Century increased from 30.0 psi unloaded to 30.5 psi loaded. This is indeed a trivial point - close enough is close enough.
Hope this helps.
simply said it was wrong. Now you have corrected it and given a good engineering answer.
I figured I covered my a** by saying if a perfect elastic vessel :-).
I realized that the equation was not accurate in the real world, but there is so much misconception about tire pressures and contact patch, that I just thought I would lend some basic concept to the discussion.
Re: loaded vs unloaded tire pressure. I kind of figured that the pressure would increase slightly, but felt that it would be such a small amount that most people could not measure it to within the repaeatability of their $2 pressrue gage. I must assume that you had a gauge with finer than 5 psi resolution :-) as many do.
I just went out and checked my gauge. It has one psi resoluton, but that is probably optimistic.
It is good to hear from an engineer with facts.
Keep keeping us informed.
It recently died and I had roadside assistance come jump it only to find steam coming from the hood after it was started for a few minutes. I took it into my local chevrolet and they want $1500.00 (which I do not have) to replace the battery and to remove the cylinder so they can replace the gaskets in order to fix the coolant leak (of course my warranty just ended a month ago). Any ideas on where I can get a better quote and quality service??
I wish I too had been privy to this information prior to my purchase.
Now I have a few questions regarding updating it:
1. Floor mats. I only noticed it today that it didn’t come with floor mat set. I’m thinking of buying one at Wal-Mart or Auto Zone. Can somebody please tell me the measurement of the front and rear floor mats?
2. Roof rack cross bar. How much will it cost and where’s the best place to get one?
3. Fog lights. How much will one cost? Is it difficult to install?
Thanks in advance!
What has happened to me is that when I drive my 05' Equinox on a trip, after I stop it and it's off for quite some time it will never start again. It is not the battery, because you have lights and all that. THat is the first thing they want to do is jump it. I have had to have this towed 2x. Once in CLeveland Ohio and now in Indianapolis In. They tow it in and find it has blown the back up fuse. THey replace it and it will blow again. THe last time they said the harnass around the transmission was to tight, so they cut a tie strap to loosen it. THis seemed to work again until I took it on a trip again. This only happens when I drive long distnaces. Now they tell me that they have replaced the fuse again and also have rerouted the harness wiring for the transmission. I am driving 3 hours tonight to pick this up and then 3 hours back home. I guess if it happens again at least I will be at home with it. But I have had some other wierd things happen. Like all of a sudden my drivers window will go down a little by it's self. It also will start by it's self when you put the key and just barely start to turn it. THey tell me there is nothing wrong with this. I have only had the car 13 months. It only had 10 miles on it when I got it. I'm afraid to drive it out of town again for fear this will happen again.
Has anyone else had any of these types of problems? Would love to hear from you.
Let us know
On my 2005 Equinox I was driving at a school zone speed when I noticed I wasn't accelerating when pressing on the gas pedal.. the traction control also lit up during that time. I stopped on the roadside and turned off the ignition. I tried to start the car back but the engine would only crank up and not start totally. I had it towed to the nearest dealer, they said it was a fuel pump problem and a busted fuse. Car is 4 mos. past warranty with 34000 miles.. repair cost was $700.
I just bought a 2008 Chevy Equinox and am very happy with it so far. I have a question about extended warranties. The dealer offered me a 5 year wrap-around extended warranty for my equinox for around $1000.
I have heard that online warranties like warranty direct are good, but I live in California so from what I understand, I can't buy online warranty in California.
Is the GM extended warranty good or does anyone else have any suggestions on extended warranties at better deals? Thanks.
I'll check this out and reply to you. I know that the older models could do it but like you said now everything is controlled by computers.
The dealer told me that they have to work on the same problem 3 times before I can do anything about this. This means that I have to deal with inhaling more mold and more chemicals. Help Me!!
If it's coming from the vents, there was an issue about bad antifreeze but that was in the early 2005 models and I've heard they fixed that problem. The antifreeze instead of being an orange/pink color turned brown with residue in it caused by bad radiator hoses.
Did you check your "spare tire well"? Some Equinox had water in there and that's where their bad smell came from. Stagnant water.
Heyyyyyy! (thumb up) I'm a "Fonzy" fan myself.
All vehicles have a transmission of some kind, either automatic, which may be of a normal torque converter and gear type of a constant velocity transmission that is of more recent design, and is usually found on smaller vehicles. The other type is a manual transmission, where you have to shift the gears yourself, or as of very recently a computer and control mechanism do the shifting.
Anyway a FWD vehicles has a transmission that is connected to the front wheel instead of the rear wheels.
Regarding a sealed transmission, it is not uncommon for auto transmissions to no longer have a dipstick to check oil levels. Transmissions do not "use" up their oil by burning a little every time you run them, like an internal combustion engine does. Hence, unless you develop a leak (like you did) the oil level is not going to go any place. So why bother to check it. I have owned many cars with auto transmissions and have never ever had to add oil to them.
By "sealing" the transmission the danger of overfill is reduced/eliminated.
I guess only God and you know what that O ring is all about.
Well, at least, it's fixed and didn't have to dig in my pockets cause it's still on warranty.
My original 4 seasons are 235/65/16 and I can't seem to be able to find that size in winter tires (even on tirerack). Is it the same size in winter tires or different than the 4 seasons ones?
This is what I found on a post dated (jan 18 2007) # 1021.........
(I took my vehicle in to have the water leak in the spare tire well fixed. They removed the bumper and welded something and seemed to fix it but after getting 3 0r 4 inch rain last week the water is back (about 2 inches deep) Is there anyone that has gotten results in fixing this problem that could reply to me and let me know what you did to fix the problem and what dealer fixed it). You can always make a "search" in the search box at the top right of the page by typing the cue words ex : water, well, spare tire.... and that's going to take you to all the posts with those words in. Sorry, I couldn't reply right away, I was gone to the cottage for Christmas.
replaced the evaporator coil on the AC, replaced the carpet, cleaned the interior 3 times with a bissell rug steam cleaner, replaced all of the sound foam, deodorized, ionized, deodorized again, and sealed a seam up in the wheel well that was near a vent for pressure in the vehicle. I really do not know what else. They called me from the dealership on Thursday, 12/27 and told me that the car still stunk. If the black mold will not kill us the chemicals used to try to mask the smell will. I'm really upset and looking into the lemon law at this point. I think this is a health risk more than anything at this point.