I found this article while researching the question of where to put a pair of new tires. What is amazing to me is the lack of critical thinking and the assumption that common sense overrides an expert's recommendation without examining the reasons behind that recommendation.

All tire manufacturer's that I've found who anser this question on their web sites agree that the new tires should be placed on the rear, regardless of which are the driven wheels. (There is a caveat about non-radial tires though.) The best article explaining the reasons was found at http://seattletimes.nwsource.com/html/motoring/2003094616_bergholdt30.html. Other articles that I stumbled upon explain the reasons for using nitrogen instead of air in the tires. The main reasons are improved mileage due to less leakage than plain air due to larger molecules that the oxygen molecules in air, the lower moisture level, and the absence of oxygen to react with the rubber. The nitrogen-filled tire pressure fluctuated much less than that in air filled tires. A few years ago, just after having two new tires placed on the FRONT of my Integra, I was driving a little fast for conditions on a downhill curve after a rain. The rear came around and I spun around until stopped by the curb. Thankfully with no damage to the body or suspension. This was an example of the oversteer avoided by placing new tires on the rear. I'll never again put new tires on the front.

The times that I have had a rear tire blow, I have had trouble even feeling the flat until I changed direction. Then the response can be mushy or unstabel, but still controllable. The times I have had a front blowout, the steering became unpleasant and unstable. I drive a 2002 S-10 and and full size Ford conversion. I much prefer the rear tire loss. BTW- most of my blown tires are from the stones on gravel roads (didn't usually go flat until much later on paved roads. $175 pieces of gravel.), tho I did have nails for 5 years when new homes were built near me...

Bob,

The explanation for why the new tires should go on the rear can be found at: http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=52

Regards,

Dean (another ex-Philbrick employee)

Professional motor racing teams use nitrogen, because the behaviour as it changes temperature is much more predictable than for compressed air containing unknown quantities of water. Getting the steady-state tyre (tire) pressure just right can gain tenths of a second per lap, which is useful.

For normal road use, it makes negligible difference.

Don't see why oxygen should leak out of a tyre any faster than nitrogen - it's a diatomic molecule just the same, and a little bit bigger.

Don't know about others, but I've had 5 blowouts at highway speeds, 4 rear, 1 front. Can't say that I lost control or spun out any time. Worst case was trying to get off-road on the outer drive in Chicago during rush hour. My wife lost a rear tire at highway speeds in a loaded dodge van, and it wasn't a panic situation at all, (and a friend was driving the van, who didn't know the vehicle.)

Even when I lost a tire and it whanged the back end hard enough to trip the fuel pump kill switch, (I thought the bang was the engine blowing, because the engine quit,) I was able to bring the car to the edge of the expressway, (without power steering assist,) and I'd been doing 70.

Yay www.philbrickarchive.org. Absolutely fascinating.

Hi Bob: The "best tires on the rear wheels" is relevant for pre-ABS cars, not so much for modern ones. The reason is, that if you brake hard and the rear wheels block, the car will go into an uncontrolled skid. If the rear wheels keep rolling (and the front ones are blocked) you'll go straight. This is also the reason for the brake pressure reduction valves for the rear wheel brakes. For the viewpoint of a vehicle with a blown rear tire being easier to handle, this is certainly dead wrong. If this happens, the car will spin out of control. For a blown front tire, you'll be able to roll to a controlled stop. I've seen this demonstrated on several videos, but fortunately not had it happen to me. Btw, recommended reaction when a rear tire blows is to stomp on the brakes and hope that the ABS will save you. However, this must be done so fast (before the skid begins) that you'll probably not be able to do it. As for Nitrogen, there's a long thread about it over on www.eng-tips.com. Consensus seems to be that 1: it's a marketing spin. 2: in certain situations it's practical, as it's much easier to carry around a pressure bottle than a compressor, and Nitrogen's cheap.

Nitrogen is only a marking experiment to see if they can sell Mobil-1 Synthetic Air for your tires. :-)

Nitrogen in a tire has some advantages over compressed air. Dry nitogen vs wet air, for instance. Not much difference but some. Much the same as Monster Cable for audio speakers.

As to new tires on the rear, the fronts wear the fastest on front wheel drive cars such as the Camry. You want your oldest tires to wear out first before dry rot gets them. Properly aligned they'll never wear out on the rear. Best to rotate front/rear periodically so all 4 require replacement at the same time.

I always put the new tires on the rear because a new tire could have a manufacturing flaw and blow out. A vehicle with a blown rear tire is a little easier to handle than one with a blown front tire.

It seems the oxygen in air leaks out of tires much faster than nitrogen. When a tire is first mounted and inflated with air it will loose pressure faster than it will later in life. As air is added, the oxygen leaks out and leaves nitrogen behind. This assumes the driver manages to avoid nails, etc. by driving around them.