| > On my drive home, I liked the tires at 35 pounds. The handling | > was crisper, more secure. Ride on the freeway was smooth. On city | > streets, the ride was a bit rougher, but still civilized. | >
Well, not exactly true. They _said_ that they inflated the tires to 35 pounds (but I later realized that, well, I'd driven off and on a few times that day -- the shop worked way too fast; repaired a flat, balanced the wheels, and rotated them all in under 22 minutes. Today I measured the pressure cold and found every tire with a different pressure, all between 30 and 32. I then filled them to 35 all around to see how it'll do. (Will I ever in my life find a tire decent tire shop?)
| Although I don't have Sonata, there are several tire pressure related | issues that are universally true of front wheel drive cars. |
| - The recommended pressures are designed to create plenty of understeer | in corners. Most people don't know how to control a FWD car in a rear | end skid, so manufacturers go to great lengths to prevent this from | happening. Tire pressures have a large effect on handling, so they're | used to tune in understeer, without having to compromise other aspects | of the suspension. |
What I've found in recent years is that the car makers seem to be specifying the same pressure all-around, and it seems to be 30 lbs. Maybe I'm wrong.
| - Manufacturers are not concerned with tire wear, since tires are not | warranty items except under special circumstances. If their recommended | pressures result in premature wear, oh well... | | - Since FWD cars carry much more weight on their front tires, those | tires need higher pressure than the rears in order to support the weight | optimally. Low pressures result in premature edge wear, though that's | often masked by the normal edge wear that occurs from cornering. |
Not always true -- see below for an interesting exception.
| I've found that my FWD cars have handled best with tire pressures 2-6 | psi higher than recommended and 3-5 psi more in the front than the rear, | which varied a bit from car to car. Manufacturers rarely recommend this, | since it makes the ride a bit rougher and the handling more neutral. On | my EGT, I run 36 psi front and 32 psi rear, which provides a reasonably | smooth ride and good handling. Higher pressures improve the handling a | bit at the cost of ride quality. That should be a reasonable starting | point for your Sonata, though you may find that slightly different | settings suit your needs better.
What's an EGT? I'll keep this in mind and later fool with a distribution as you mention. |
In days of yore, shrouded in the mists of time, I owned a '62 SAAB sedan, the kind with the 3-cylinder 2-stroke engine. In fact, these were the only motors that they made. It was a really tough car that handled extremely well and was great in snow. A friend who was into racing turned me on to radial tires, so I replaced the bias tires with Michelins. At the time, one could not choose from different tire models. There was one model that fit the car and that was that. My choice was between Michelin and Pirelli, which SAAB fitted to their model that was rigged out for racing.
So, I picked up a Michelin application book at the tire shop, which gave recommended pressures for every conceivable car. Now, I notice that tire makers simply recommend the car makers' settings; hell, it keeps 'em from being sued. But then, Michelin actually tested their tires on the cars, and gave their own inflations. After all, all the car makers were putting bias ply tires on their cars and gave pressures for those -- the radial makers had to come up with their own. For almost all cars, Michelin advised more pressure in the front than in the back. But for SAAB it was the opposite, and the opposite of what SAAB themselves recommended for their normal tires. Michelin said 18 lbs in the front and 22 in the rear. This seemed most peculiar, so I wrote to Michelin for an explanation. (For whatever reasons, everyone used much lower pressure in those days; remember, this was during "yore," and shrouded in the mists.)
Michelin replied that the unusual pressures were due to the weight transfer to the rear while the car was in motion. And I got it: SAAB was (and is) an aircraft company. They only got into cars after WW II. Their cars, unusual for the time, were aerodynamic -- befitting for a company that made fighter planes. I used those pressures for years with perfect success. The car tracked as if it was on rails.
Richard