[gkmunch]

This is a weird one; bear with me.

I recently took off my winter wheels/tires and put on my factory set. 18" Style 400 wheels, Continental ContiSport Contact RFTs. Immediately noticed how much rougher they rode. Chalked that up to the harder compound and semi-cooler temps.

However, there's a sweet spot around 35-45 mph where I've been getting some harmonic roughness; seemingly from the front drivers side corner. It's not quite like a steering wheel shake when a tire is out of balance, more like a steady 'humm- humm-humm-humm' that can be felt in the pedals. Seems to smooth out at highway speeds.

So the dealer did me a favor and balanced the set, said they were a little out of balance which was weird since this set of tires has less than ~3000mi on them. Anyway, the problem wasn't solved, despite confirming that the tires were balanced, round, no flat spots, etc.

Just visually inspecting the tires I noticed the tread seemed to be backwards on the drivers side. I checked the sidewall, sure enough they all say "outside" and do not have a directional arrow on them. This is the odd part, since they are not symmetrical.

Basically, relative to rotation, the drivers side and passengers side have different slanted directional tread (highlited by the pink lines below). In person the slant is more pronounced, but the pink hash lines show what I am talking about. Also, the first picture below shows the tread is raised on the drivers side tire - as if it is fighting the direction of travel. These peaks can be felt if you run your hand over it.

So here's where my question comes in. Other 340i owners with these tires: Are yours the same way? Do they make passenger side and drivers side tread patterns, yet only have markings for Outside/Inside of the tire and not directional arrows? Do these tires just suck?

The factory already shipped this car with the incorrect rear end, I would not be surprised if they put 4 passenger side tires on the car as well...

[X2 Monstah]

I have the exact same issue with the exact same tires on my 328i. Planning on ditching the run flats and getting an alignment soon with hopes I have better luck.

[alohasurftoad]

looks like feathering. caused by improper toe, caster or camber, combination of.

also sounds like the onset of cupping

[HighlandPete]

Heel and toe (saw tooth) tread wear. Quite common on many tire types, not particularly a Continental tire issue.

Can be geometry, (needs checking) but also can be made worse by incorrect tire pressures. Setting pressure is often too low and the shoulder tread blocks distort more as tires rotate, causing the heel and toe wear pattern.

One way to wear the tire shoulder more evenly, is to swap wheels "side for side" and wear the tread blocks in the other direction. Will change the harmonics, as the wear changes its pattern towards the opposite direction.

[HighlandPete]

Originally Posted by BSM F30

I have the exact same issue with the exact same tires on my 328i. Planning on ditching the run flats and getting an alignment soon with hopes I have better luck.

It is not particularly a Continental, or run-flat tire issue. Non run-flats can wear just the same.

[gkmunch]

Thanks for the feedback! At least the tread pattern is normal, and they do not make driver/passenger side tires in this model. (I didn't think so, since there are no rotational arrows). It was just so strange to me that relative to rotation, there are differences (even as slight as they are) between sides. It's good to eliminate variables though...

If anything, I err on the side of a bit higher tire pressures. I'll have the alignment checked, and probably swap "side for side" to at least even it out.

[HighlandPete]

Originally Posted by gkmunch

Thanks for the feedback! At least the tread pattern is normal, and they do not make driver/passenger side tires in this model. (I didn't think so, since there are no rotational arrows). It was just so strange to me that relative to rotation, there are differences (even as slight as they are) between sides. It's good to eliminate variables though...

If anything, I err on the side of a bit higher tire pressures. I'll have the alignment checked, and probably swap "side for side" to at least even it out.

Definitely get the alignment checked. Often both sides will get a similar forward leading heel and toe pattern. But not unusual for one side to be prominent, if the geometry is slightly out and/or if steering correction is needed. Does the car steer well and straight? Any camber sensitivities, or slight pull?

[gkmunch]

Originally Posted by HighlandPete

Definitely get the alignment checked. Often both sides will get a similar forward leading heel and toe pattern. But not unusual for one side to be prominent, if the geometry is slightly out and/or if steering correction is needed. Does the car steer well and straight? Any camber sensitivities, or slight pull?

It seems to track straight and steer well. The car will pull relative to road pitch or trenches, but nothing abnormal from any other car I've driven. My winter set of wheels/tires rides smooth and true as well, which lead me to further scrutiny of the OEM wheels and Continentals to see what the heck was going on.

[BEAR-AvHistory]

Try getting some white liquid shoe polish & paint some stripes across the tread & slightly up the side wall.

Do a hard run & check the polish line. Middle gone but outside still there too much air in the tire. Outside gone but middle still there not enough air. Line continuous but shoulder part gone the tires are rolling under when you turn need a bit more air but not enough to bow the middle out.



Also could indicate poor alignment. That is the hardest one for a quick & dirt check to solve.