[simianspeedster]

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I haven't hidden the fact that my wife and I are disappointed in the suspension tuning on her new F30 328i Luxury Line. It bobs and weaves far more than any BMW I've ever experienced, yet the impact harshness is often worse than my 2011 M-Sport 335i coupe -- kind of the worst of both worlds.

To date, I've just chalked it up to BMW softening the base (i.e. non-sport) suspension to make the F30 more liveable for the increasing share of 3 Series buyers who want a nice, luxurious German sedan but who aren't terribly interested in the sports sedan experience.

This morning I took my coupe in for service and secured an F30 328i loaner car, a base model. I expected it to drive similar to my wife's car, an in many ways it does, but the suspension tuning feels different to me -- it's a bit firmer, bounces around less and absorbs impacts better. It just feels better balanced all around.

So now I'm wondering if it's possible that the Luxury Line suspension tuning is different than the base trim and/or the Modern Line. My wife's car has more features than the stripped loaner car so it weighs more, and it has 18" rims and lower profile tires, but those should be the only major differences and neither seems like it would be enough to explain the difference I'm feeling between the two cars.

I've driven a lot of cars in my day and I'm very detailed oriented, so I really don't think I'm imagining this distinction. Any ideas?

[simianspeedster]

I'm not sure I understand the question. Are you wondering if BMW may have left a tow hook connected somewhere underneath the car (i.e. it wasn't prepped correctly)?

A while back, a posted in another thread suggested I look to make sure the suspension shipping blocks were removed just in case that was an issue. I took a cursory glance inside the wheel wells and didn't see anything obviously abnormal.

[simianspeedster]

Originally Posted by simianspeedster

I'm not sure I understand the question. Are you wondering if BMW may have left a tow hook connected somewhere underneath the car (i.e. it wasn't prepped correctly)?

A while back, a posted in another thread suggested I look to make sure the suspension shipping blocks were removed just in case that was an issue. I took a cursory glance inside the wheel wells and didn't see anything obviously abnormal.

Weird -- this was in response to a reply by E90Fleet which seems to have gone missing or been deleted somehow from this thread. He asked "Does your wifes car have the BMW factory Tow hook ?"

[bimmerjph]

I don't think BMW would got to the extra cost to do that. Have you told your service adviser about your problem?

[E90Fleet]

Lines do not affect the springs

There are basically 2 sets of Springs for the standard USA suspension
When multiple heavy options ( like sunroof, HK, ect) are fitted ) the springs change from the lighter car ones to the heavier car ones.
But you should not feel the difference.


Have you looked with a flashlight at the springs on the car to see if there maybe is a forgotten shipping block or something in them ?

[simianspeedster]

Originally Posted by bimmerjph

I don't think BMW would got to the extra cost to do that. Have you told your service adviser about your problem?

I just talked to my wife about it and we agreed we need to take her car into the dealer to have it checked out soon. Her car also has a persistent dash squeak/rattle around the idrive/Nav display screen that they need to fix anyhow.

I'm headed back to the dealer this afternoon so I will ask our service advisor what he thinks -- he's quite good in my experience.

[E90Fleet]

Originally Posted by simianspeedster

Weird -- this was in response to a reply by E90Fleet which seems to have gone missing or been deleted somehow from this thread. He asked "Does your wifes car have the BMW factory Tow hook ?"

Sorry, was thinking of the E90 there, so deleted the post.

[E90Fleet]

One thing to check also is the tire pressure.
Too low on runflats can make them feel harsher

[HighlandPete]

Are you sure both cars were on the same suspension?

Even if they are, wheel size could be the issue, some E90 models would feel very different on 17" and 18" wheel sets. Then there is the tyre specification as well, different brands, different ratings? Not one on an all-season and the other a summer tyre?

HighlandPete

[HighlandPete]

Originally Posted by E90Fleet

One thing to check also is the tire pressure.
Too low on runflats can make them feel harsher

+1

HighlandPete

[micknugget]

If there proves to be nothing wrong, I would have to say it's the wheel/tire combo. The 18"s will give you a harsher ride and the 17"s sidewalls will likely have more flex which will possibly mean the suspension will move less.

[HighlandPete]

Originally Posted by micknugget

If there proves to be nothing wrong, I would have to say it's the wheel/tire combo. The 18"s will give you a harsher ride and the 17"s sidewalls will likely have more flex which will possibly mean the suspension will move less.

Adding to your comment, in my experience with run-flats, some combinations seem to amplify road imperfections, rather than the feeling of the tires helping the suspension to absorb the blemishes.

I know with the F10 5-series the 19" appear to work better than the 18", IMO, there is more bounce and less refinement from the 18". So I'm not surprised the F30 could have variations.

Incidentally the F30 I test drove, a 328i, had 18" Goodyear Efficient Grip ROF (summer tires) on standard suspension, and that worked very well, the best 3-series on run-flats I've ever driven.

HighlandPete

[shanecarmaster1]

Check your tire pressures.

[simianspeedster]

Thanks for all the feedback.

It does seem certain that there are no suspension differences between the loaner (Base Model) and our car (Luxury Line), so that answers my original question. I talked to our service advisor when I dropped off the loaner today and he agreed with what's been posted so far. I'll check the tire pressure this weekend and if that doesn't address the issue, I'll take it in to get checked out.

I still wonder how much more the F30 wheel/tire combos weigh compared with the E90s because unsprung weight is the enemy of ride and handling. The F30 wheels/tires are an inch larger in diameter overall, so that has to be a significant factor.

I'm still eager to drive a Sport Line when my lease end is closer -- my hope is that it will wipe away any remaining concerns.

[PrinceBarin]

Just wondered if you had checked your tyres and notice any improvement?

Most luxury owners on this site seem very happy with their cars but I remain concerned by the unfavourable comparisons being drawn between the standard and sports suspensions. Nothing I have read in the press would lead me to doubt your original conclusions regarding the standard suspension on the F30 but it would be reassuring to find out something was amiss (and also fixable). Either way, I'm going to be double-checking my tyre pressures just as soon as my car arrives next week!

Hope you find a solution.