It's so nice to have Top Gear around. You guys don't just feed us a †monthly dose of motoring goodness but also you help people who need advice on our car problems. One can’t ask for better people around.
On to the "helping" part now, I would just want to ask if all recommended cold-tire temperatures are applicable to all tire sizes regardless of the brand. For example, is the recommended cold-tire temperature of 195/65 R15s of Yokohama the same for the 195/65 R15s of Falken? Do we need to consult tire brands for their recommended cold-tire temperature?
Well, thanks for accommodating my question. I've been losing sleep the past few nights just thinking about this!
Thanks again, and more horsepower to you all! God bless!
That's what we're here for--to give all the car guys and gals out there a helping hand.
I'm a little confused with your question but I'm assuming you meant cold-temperature tire pressure. If I'm correct, then the short answer to your question is yes, they are the same.
There will probably a small variance in how they expand (or increase in tire pressure) as the tires heat up with use but in general they will be close enough to be considered the same.
Tire pressure, of course, plays a critical role in car control, vehicle handling, tire wear, fuel consumption apart from ride comfort.
Our cars have been designed with tires that are part of a matching system along with the suspension to give our vehicles their own unique ride, handling and vehicle characteristics.
Vehicles designed to be commuters, for example, will typically have long wearing tires that give adequate grip under most conditions while still retaining a decent level of comfort. You'll also notice that they have a recommended tire pressure. Deviating from this tire pressure, like say, lowering the tire pressure to achieve a perceived more comfortable ride will adversely affect the fuel economy of the vehicle. It will also unduly wear down the tire. Over time vehicle handling and ride comfort will suffer as the tire wears down unevenly. This will further adversely affect the fuel economy as well as the underchassis of the vehicle as the steering and suspension components are subjected to forces generated by a tire that's now uneven (and also unbalanced due to the uneven wear). The net effect is there will be an oscillation that or swaying of a particular corner of the vehicle, which is most perceptible during low speeds but not noticeable when at normal vehicle speeds. This barely perceptible oscillation will accelerate the wear and tear of, at the very least, your tie rod, steering rack ends and ball joints.
When they do wear down beyond a certain point will make for poor car control manifesting in the kalampag we hear as the car goes over small road imperfections.
On the other hand, increasing the cold-temperature tire pressure within certain limits to achieve better fuel economy will have lesser issues on wear and tear at the expense of poorer traction as the tire contact patch is reduced. Ride comfort will also suffer as the tires become firmer with the increased tire pressure. A rule of thumb is not to deviate from the recommended cold-temperature tire pressure more than 3psi to 5psi unless you know what you're doing or are out to achieve a certain effect on the vehicle dynamics of your car.
You will notice that every time you change your wheel and tire combination or tires for that matter there will be a change in how the car feels to you.
I hope that helps clarify the issue. Have a good night's sleep later!