An inspection by the local independent shop revealed that the suspension was fine. The mechanic asked me if I knew that one of my tires had a load index of 99. I did not. Did I also know that my car is supposed to have tires with a load index of 103? No, I did not. I did not even know what a load index was last week.
This is a shot of the door jamb sticker. I suggest that you look at it again. Previously, I've only paid attention to the size of the tires and the recommended pressure. I didn't know the number (103) after the tire size was the load index. According to this chart, a 103 rated tire has a load capacity of 1,929 pounds (875 kilos).
When the previous owner of the Phaeton suffered a flat, he replaced it (probably inadvertently) with a Continental tire with just a 99 load index, which has a capacity of only 1,709 pounds (775 kilos). Given the mass of the Phaeton, the sidewalls on the weak tire had been slowly warping and collapsing. This explained a lot of the vibration.
And since the other three tires were going bald, I ordered a full set of Continental ExtremeContact DWSs from Tire Rack. They were installed today.
But while I was waiting for the install, I realized something. Three of the four tires came with the car when it was originally purchased in 2005. They must be seven to eight years old! They were never changed because the car did not have that many miles and they still had tread left. But with the dry and hot climate (the car was in Arizona from 2005 to 2011) and infrequency of use (the car was driven twice a month by the previous owner), the three tires were probably deformed. Why didn't I think of this earlier? What a dope I am. This probably also contributed to the vibration.
You know how when you are used to seeing something everyday, you don't notice that there is something wrong with it? Well, the old tires were bald. But I didn't realize how bald they were until I saw the new tires on my car. By comparison, the new Contis are like knobby off-road tires. I briefly took it on the freeway. The ride was beyond perfect. What a difference! (I hope it's not a placebo effect.)
Glad it was a simple (yet costly?) fix. It's the same thing with shocks. You don't realize how bad they were until you replace them.
ReplyDelete@Edvin: I needed the tires anyway and they ended up costing slightly more than the Acura's. So I'm happy. The OEM tires, which got poor ratings, would have cost 70% more!
ReplyDeleteOne of the few things on a Phaeton that aren't more expensive than normal :)
ReplyDeleteI've paid a lot of attention to the load index of tires having driven fully-loaded Vanagons all over our little continent. Often people will replace flat tires on them with cheap regular car tires (who's up for a Baja surf trip?) which can be ok around the city but not for long trips with big loads.
Oh to be able to buy a new Phaeton-like car and drive it once a fortnight. And the sell it at a massive loss.
ReplyDeleteAlso, how's the spare?
@Lukas: I know, right? The previous owner has almost two dozen cars. I think his daily driver is a Golf diesel, which is pretty cool.
ReplyDeleteI didn't even think of the spare. I'll probably have it replaced at the next oil change.
Did the Phaeton ever make it to Oz?
Oh, and the car is so responsive and comfortable now, it's like night and day. The car feels brand new. And it was still pretty nice last week with the old tires.
No Phaetons in Oz as far as I know - there are conflicting articles on the web about it.
ReplyDeleteVW is (strangely) seen as a prestige brand here, but I think even they knew the Phaeton was a bit of a stretch, when an S class or 7 could be had for similar money.
My crappy old car feels all nice and floaty on new tyres too - perhaps the rubber is initially softer or something?