Tires: all weather tires, proper inflation pressure, volvo 240 wagon

Question
Hi Barry, I have a 91 volvo 240 wagon which I purchased used with a practicly new set of tires. Unfortunately the tires I have seem unsuited for poor weather conditions.  The car has rear wheel drive and in wet weather the rear tires tend to spin from a wet start and in the snow the car tends to slide on both ends.  Can you explain to me what I should be looking for in a good all weather tire that will hold the road in all conditions?  
           Thanks, John

Answer
John,

Sorry to take so long to respond, but Allexpert's file server seem to be full and wouldn't let me post anything

Tires are always a compromise between mileage and the ability to grip the road surface.  Anything that improves grip, hurts mileage.

And it is difficult to offer advice without knowing the driving conditions you are experiencing.

As a general rule, if you live in the northern part of the US, you are going to need snow tires in the winter.  All season tires can work in snow if they are a fairly open pattern with loads of edges.

For hydroplaning resistance, you want straight grooves.  But for other types of wet traction, the UTQG letter for traction is based on a wet traction test and ought to provide a good basis for comparison.  Here's a good explanation of UTQG rating:

http://www.tirerack.com/tires/tiretech/general/utqg.htm

But there is one thing that might help with what you have now.

Look for the placard on your vehicle.  The placard, among many things, tells the original tire size and the proper inflation pressure for that size.  The placard is usually located on a doorpost or in the glove box.  

I like to use 3 to 5 psi above the placard.  I get better fuel economy, better tire wear, better wet traction, better snow traction, better steering response, better tire durability, and only give up a bit of ride harshness.

"They" say you should check your tire pressures once a month.  Don't trust the guys at the shop to do it.  These guys are paid by the hour and this is one of the easiest things to shortcut.  Besides, there are a lot of mechanics you don't know where to look for the proper inflation.  No, it is not on the sidewall.

Buy yourself a tire gauge - a $5.00 pencil gauge works just fine, but I prefer the pistol grip digitals because they are remarkably accurate.  The check takes all of 5 minutes and it is the cheapest safety check you can make.  

Hope this helps.