Tire Talk: You don't really need nitrogen
Q: We bought a used Volkswagen in Phoenix and the tires used nitrogen. We just started putting in regular air. Is that OK, or do we need to buy new tires? Also, on Dec. 10 I put air in the tires but by Jan. 7 the low tire pressure warning light was on. I took it to a local maintenance place and they said my tires should have 40 psi. Are they right?
A: You do not need new tires. It is perfectly fine to top up a low tire with air even though it was originally filled with nitrogen. Everyday air is made up of 78.09 per cent nitrogen anyway. Some shops upsell clients and charge extra to put nitrogen in the tires, making all kinds of claims about improved tire wear. In everyday driving these claims should be taken with a grain of salt, if nitrogen is free take it, if they want you to pay for it, I?d give it a pass.
The fact that you filled the tires and then had low pressure in less than a month indicates you have a slow leak. If a tire has a leak it matters not, nitrogen or compressed air, it needs to be looked and repaired.
You don?t state the model or year of your VW, so I cannot help you on pressures. Check the owner?s manual and go by what the VW factory says. Usually there is also a decal in the door jamb or gas filler door stating the correct pressures. If they are not there, check with your local VW dealer. You need to get the pressures right, too low or too high you wear out the tires faster, plus too low and you use more fuel.
Q: I have a 97 Buick LeSabre in almost mint condition with only 75,000 km. on it. I would like to replace the tires with whitewalls, but it seems that they are not available anymore. It takes P205/70R15?s. Is there anywhere that they may be available in the GTA?
A: I know of only one seller of classic whitewall tires in Canada and that is Ken Simpkins at Classic Tire Mart in Bobcaygeon (416) 575-9972. (classictiremart.com/home.htm.) Ken used to run a very large performance-oriented tire shop in Mississauga.
If you prefer to get a look at more selection you can visit these American retailers: classicwhitewalltires.com, widewhitetires.com/
I have not had any personal experience with these sites so I cannot endorse them.
Q: I have purchased a 2002 RSX (base model) which came originally on P195/65R/15 tires. The 2002 RSX-S model comes with P205/55R/16 tires. I got a great deal last year for 18? rims that came off an RSX as well, but the tires are almost worn and need to be replaced. What might be the best 18? tires that will suit my 2002 RSX?
A: You are taking a big step moving a car that originally ran on 15 inch rims to 18 inch wheels. I hope these are lightweight wheels. Going to a ?plus 3? (15 inch to 18 inch wheels) is a big step and weight matters a lot.
For instance, a P195/64R15 tire typically weighs about 21 pounds. A P225/40R18 (the size you will need) usually weighs around 26 pounds. So, assuming the 18-inch wheels are also about five pounds heavier, we are looking at an unsprung weight increase of up to 10 pounds per corner. That is huge.
The heavier weight will make the car less willing to react to the steering as quickly, and the gyroscopic effect will make the car want to follow road contours much more than you are used to. Plus, moving down to a 40 aspect ratio will stiffen the ride.
The P225/40R18 size you need falls into the extreme or max performance category, which means big, sticky heavy tires. Too much stick can actually be a bad thing. Three tires I would consider (in order) are the Bridgestone RE970AS Pole Position, the Continental DWS, the General G-Max AS-03 and the Kumho Ecsta SPT. Of these, the General provides the best dollar value and is also the lightest tire at 21 pounds.
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