what's normal tire wear?

[dsames]

This being my first BMW, I'm wondering what "normal" tire wear looks like for regular street use. I have Kumho712's on the car for about 9 months now (I'll have to figure out how many miles that is... <20K, anyway), and it looks like the inside edges of the rears are wearing quite a bit faster than anything else. The fronts aren't quite as worn out, but there is a similar pattern. Outside edges are less worn than inside, and there is definitely wear in the middle. Tire pressures are whatever is recommended on the info panel (don't recall what I set them to at the moment).

Any thoughts?

Thanks,

Dave

[1996 328ti]

Is your car lowered and what model car is it?

[dsames]

No - it's not lowered, it's an '99 328i. I did put a '98 M3 staggered wheel set on, and the relevant tire sizes, however.

Thanks

[bren]

I don't think it's entirely abnormal for the insides to wear a bit faster than the outsides (so long as it's even on both sides of the car.)

Of course if the alignment hasn't been checked in a while it certainly wouldn't hurt.

[Doby]

How many miles are on your car? The springs do get old and sag. With that sagging, the car ends up with more negative camber and will then wear the inside of the tires faster then the outside.

I'd suggest the when you get new tires, have it aligned again.

[AG]

Worn shocks and bushings could do it too, no?

[Doby]

If the springs are sagging, then yes the shocks are done too.

There is a camber problem in the rear causing the inner tire wear, but since he has ~20k miles on the tires, I wouldn't think the RTAB's are that bad. Bad RTAB's can cause the rear tires to wear down in ~5k miles. If they were bad, I would think that the tires would have been toast before the 5K.

[dsames]

Okay - some more info - ~75K on the car. I haven't had an alignment done in the time I've had it (since ~38K miles). I don't recall there being an alignment in the service records, but I should check. The wear appears pretty even on both rear tires, and as I mentioned, some on the fronts, but not as much.
Suppose I should have the alignment checked when I get new tires next time around.

On a side note, are there suspension components that should be replaced at some regular interval? I've heard some claims that control arm bushings go around ~60K, but I haven't noticed any significant changes.

Thanks!

Dave

[Doby]

You stock shocks/struts are probably toast, along with your LCA bushings, and RTA bushings and your rear shock mounts.

[maditalian]

You stock shocks/struts are probably toast, along with your LCA bushings, and RTA bushings and your rear shock mounts.

how often sould one change the shocks/struts and springs
mine have 31k and my car is a 01 m3, a guy i know whats to sell me his zcp package m3 suspension w/ like 1k miles on it (he got H&R's) for like 350 bucks and i have been thinking about it
watcha guys think i should do ?

[ChosenGSR]

how often sould one change the shocks/struts and springs
mine have 31k and my car is a 01 m3, a guy i know whats to sell me his zcp package m3 suspension w/ like 1k miles on it (he got H&R's) for like 350 bucks and i have been thinking about it
watcha guys think i should do ?

I think thats way early, also I would go aftermarket if I was to to upgrade.

[OwnedbyDuncan]

Shocks and springs. Shocks typically start to go at around 40k miles under normal conditions. Springs under normal conditions dont really need to be changed. If you track the car or do Autox around 75k.

If you are going to replace the shocks and are considering new springs. I would do it all at once. Same labor costs or time if you are doing it. You can replace the bushings too. And only pay one time for alignment. I prefer stiff springs and small sway bars. I use the sway bars to tune the car. Big bars have a tendency to rip the mounts out. Also find a quality shop to do the work and the alignment. Not Manny, Mo and whoever. Shocks bars, springs and camber plates need to be installed correctly with no preload etc. Alignment done with a full tank and if you are lucky with you in the car.

[dsames]

Unfortunately, I'll have to show ignorance here, but, what are LCA bushings, and RTA bushings?

So, now I have to ask the obvious question - what are good replacements for these things? Might as well upgrade while I'm in the process, right?

[1996 328ti]

It might be time to add a glossary.

LCA Lower Control Arm
RTA Rear Trailing Arm
RTAB Rear Trailing Arm Bushing

[OwnedbyDuncan]

Forgot to mention make sure the springs you buy work. Many years ago when I was looking for springs some from major suppliers just did not work. Some were softer than stock, some bottomed out and others suffered from coil bind. These were springs from a big time BMW/Porsche after market supplier located in Alexandria, another firm whose initials are ST and a big name spring manufacture whose name begins with E( did buy their comp springs). A major West Coast BMW tuner would not give me their spring rates. Hell for what they wanted for their suspension packages they should have tested each spring individually and put the spring rates on a nice polished plaque. If you autox or do schools do some research and ask questions. There are very few shops out there who know about springs, shocks, bars and camber plates etc but they will be than happy to take your money and install them. Having coil bind down the chute at Summit Point is not the fast way and may be a real scary way!