visible rear negative camber
 

The 3's rear wheels have quite visible negative camber (shop manual says is 1deg10 to 1deg29, from no load to full load), while the front only has 0.11deg negative camber. Just standing in front ot rear of the car you can see the apparent rear negative camber. Anybody know why?
________
Amber

RE: visible rear negative camber
 

It makes it handle better....as the vehicle transfers weight to the outside tire in a turn, the tire patch actually flattens down to the road. That's one of the reasons a stock Mazda3 handles 0.86-0.87g on the skidpad (same as a 350Z)

RE: visible rear negative camber
 

sstlaure, thanks for the note. i didn't know a stock 3 can handle almost to 0.9g, which is really close to those hi perf cars. 1-deg of camber has an offset of 0.01745 per inch, so for a 16in wheel, the entire wheel diameter is ~24 inch, which produces 0.42in offset, which if you look closely, is noticeable.

this reminds me that virgin said he does fast cornering all the time......have you noticed uneven wear of the inner edges of the two rear tires? how long do you rotate, and how? (i know the manual says front to rear, would it better to swap the two rears or criss-cross (not for the asymmetrical tires of course).

Another question is that what tires are good for ~1 neg camber for straight highway driving?
________
Whip Vaporizer

RE: visible rear negative camber
 

I had pretty good luck with Toyo Proxes FZ4 (not sure if they make them anymore, but the wear rating was 300....higher numbers mean they last longer, but most likely don't perform as well from a handling standpoint). The inside edge definitely wears first. My tires were a directional tread, so I could only move them front/rear (not side to side as that would have required unmounting and remounting the tires.). I rotated about every 10,000 miles and got ~40K out of a set. Although I ended up having staggered tires (newer ones mounted on front) when I had a tire get destroyed by a pothole. The rears had ~20,000 miles on them when I got the new fronts, so then I ran the fronts to ~20K, moved them to the rear and got new front tires again.

RE: visible rear negative camber
 

Theanswer is none (imo.) No tire will wear well with so much negative camber. Race cars use a ton of neg camber and they need to change tires all the time. If you've ever looked at a racing slick removed from the front of an SCCA Production car (right and left turning cars) you would see that the inside edge is nearly all (or completely)gone where the outside survives a bit better, even under those drastic conditions.

I know I'm gonna catch a lotta flack for this, and I do believe the Mazda engineers got nearly everything right on the 3 (except it needs more power, better clutch feel, better A/C, a lower stance, etc, etc.:D) but seriously, I believe they dialed in too much negative camber for a street car. It's not practical for your daily driver to burn up rubber that way.

As far as having fun cornering hard, yes, I do that. But if you also remember I said that I had redialed in the rear suspension (admittedly by trial and error, though w/o any error that I can detect.)
You may remember that SST and I were discussing whether the cam bolt in the rear control arm adjusts for camber or toe. I can only say that by pulling in the cam bolt in the rear lower control arm and effectively shortening the control arm, that my rear tires wear much better now, and that corners that used make my rears howl @ 55 can now be easily taken 10mph faster than that. A FWD is susceptible to understeer anyway. Having so much neg camber only makes it more so.

The AM tires I had replaced the OE BadYear's with, Falken's and now the Kumho's, are both directional, and I try to make a point to rotate them front to rear (same side) every 5k miles. W/radials, I have always rotated only front to rearanyway. I was never a big believer in side to side rotations.

RE: visible rear negative camber
 

Virgin/Sstlaure,

Appreciate very much on sharing your experience. The rear static negative camber seems to be a common thing on recent car models. I've looked at cars in my company's parking lot and noticed many cars have that. So maybe it's a fashionable thing. The mazda3 spec is 1deg10 to 1deg19, but the tolerance is +/-1deg, and the diff btw left and right <1.5 deg. So if they dialed in -2deg read camber, it's still within spec, awful. Hope the tire company can develop some tires for the neg rear camber. For now, we'd have to rotate them more often.
________
Laguna Heights Condo Pattaya