[Drivaar]

Hi everyone,

After a lot of thinking, I've decided to keep my 2007 E90 335i sport package with ~110K miles on it, since it's doing fine and there isn't anything on the market I'd like to move to.

But I need to soften the ride considerably because of some neck problems I have.

I want to:

- Replace the 18" wheels & tires with 17"
- Replace the Koni FSD shocks with OEM non-sport shocks
- Replace the springs with OEM non-sport springs

Since this is my first time with these kinds of changes, I have some questions:

1. If I switch to 17" 225 width tires all around, probably Michelin Pilot Sport A/S 3+, will the rears be able to engage in 1st gear? (Don't want them to spin!)

2. What do I do with my old wheels/tires/springs/shocks? What's the best way to sell them? I have:

- a set of half-worn rears (Pilot Sport A/S 3, 225/35/R18)
- a set of OEM sport package 18" wheels (staggered)
- 4 Koni FSD with ~60K miles on them
- 4 BMW OEM sport shocks with ~40K miles on them

Thank you very much for any advice!!!

[YasF80_SLO]

Have you checked out a Non Msport F30 335i, instead of e9x. In terms of comfort its WORLDS better then e9x. If not and you dont mind replacing the current car, I would check out a 2013+ 335i NON Msport.

[Bluewater328iT]

I don't recommend taking sport package stuff off of your car. Sport package is a rare option and taking it off will make it hard to sell your car. Trade the car for a non-sport package car or one that you can test drive to make sure it suits your neck issues.

I had neck issues and stretching, sitting in a hot tub, and specific yoga and other movements helped a lot. But riding in a car never bothered me much. Sitting at a desk did.

[Drivaar]

Thanks Bluewater328iT and 2013_E92 for your comments!

The trade-in value of the car is already below $8K, so I'm not worried about that...

I could always get another car, but that's a whole lot more $ than switching out these parts, as the rest of the car is really great.

The main issue I'm having is with the Koni FSD shocks and certain types of sharp dips on the highway -- the FSDs are more comfy the rest of the time, but for those bumps, they get into their "stiff" mode, and it's very hard on the neck. And where I live now, the roads are quite terrible.

I have thought a *lot* about this, and I would be very grateful for any answers to my specific questions. (I know it's hard, because on the forums there is always a tendency to answer a different question from what's asked, often in the spirit of being helpful. ) Thank you!

[Drivaar]

(bump) Any advice on my question list please? Thank you!

[Greyfox]

As long as you keep the correct circumference on the tires, you should have no problem. 225/45x17 is stock on BMW's. I actually run that size on 8.5 x 17 rims.

But I would get away from sport tires. Go with Continental DWS. Wife has them on her 328i with M Sport Suspension and it is a very smooth ride. I have more issue with her sport seats than the suspension though.

And as for purchasing non-sport suspension... I would go to a local auto salvage and see what they have. You probably could get complete struts, rear springs and shocks off a low mileage car for under $400 total. http://www.car-part.com/

[Drivaar]

Wow, that's pretty cool to know, Greyfox! How do I know if they are damaged though? If a part is grade A, is it 100% undamaged? Thank you!

[Greyfox]

Originally Posted by Drivaar

Wow, that's pretty cool to know, Greyfox! How do I know if they are damaged though? If a part is grade A, is it 100% undamaged? Thank you!

Honestly, that "Part Grade A" is subjective... and Lord knows there are a few dubious characters that have questionable honor and ethics. But for the most part, since it has become a fairly reputation driven business, the majority of the salvage yards are okay.

But before purchasing anything I would do a thorough inspection of the part or have a mechanic do it. The yards usually will have documentation with the parts stating mileage, what damage was done to the car, etc.

There are some yards that now actually will post pictures on their websites of the salvaged vehicles so you can see what the vehicle actually looked like. ie.. look the parts up on that website, find something you are looking for then go the yards website.

[Drivaar]

Any advice on my questions? Here they are again, for your convenience.

1. If I switch to 17" 225 width tires all around, probably Michelin Pilot Sport A/S 3+, will the rears be able to engage in 1st gear? (Don't want them to spin!)

1b. If I go 225 width all around instead of 225 front/255 rear, will that cause any dramatic handling differences in daily driving? I expect that it'll lead to a little more oversteer in extreme conditions, but I am not expecting to reach those limits these days.

2. What do I do with my old wheels/tires/springs/shocks? What's the best way to sell them? I have:

- a set of half-worn rears (Pilot Sport A/S 3, 225/35/R18)
- a set of OEM sport package 18" wheels (staggered)
- 4 Koni FSD with ~60K miles on them
- 4 BMW OEM sport shocks with ~40K miles on them

Thank you very much for any advice!!!

[Bluewater328iT]

Check this website for the tire sizes recommended by BMW:

http://felgenkatalog.auto-treff.com/

As long as you use 17" or 18" tire sizes recommended by BMW, you should not see any dramatic differences in handling, any more than you would see changing brands of tires. You might find 17" are slightly more comforable due to more sidewall between the wheel and the road. If you had staggered rims before, and your 17" is staggered, the difference is minimal. If you go with same width front and rear 17" and you had staggered before, you will reduce oversteer, but not dramatically, especially if you use 8.5" 17" rims all around.

You can list your used stuff on this forum, craigslist, and eBay. Take pictures and write a detailed description of what you have and how many miles are on them. For the tires, measure the tread depth, list the date codes, and note any defects in the wheels like curb rash. Be prepared to ship them unless you specify local pickup only. If you auction them, make sure the minimum bid covers your shipping and sales costs.

[Drivaar]

Very helpful, thank you Bluewater328iT! (I've seen you help a lot of folks here with detailed answers and I'm very grateful!)

[thecadman99]

You can also go up one aspect ratio size on your tires to get more rubber between you rim and the road. I did that with my sport packaged 330i, and while its not extremely different, it did help with comfort, the speedo was even more accurate.

[Drivaar]

thecadman99: Wow, that's a great point!!! Thanks -- that would save me a ton of trouble...

Can anyone comment on the effect on comfort of using:

225/45/R18 [front] + 255/40/R18 [rear]

instead of

225/40/R18 [front] + 225/35/R18 [rear] or
225/45/R17 [front] + 255/40/R17 [rear]?

Can I go as far as trying 225/50/R17 + 255/45/R17??? I figure that would be pretty comfy!

People always talk about wheel size as being related to comfort, but really it should be about the aspect ratio, right? i.e., 225/45 should be equally comfortable whether on 17" or 18" wheels, no? Because either way there would be 225 * 0.45 = 101.25 mm of cushion in terms of "tire thickness"?

Thank you so much, thecadman99, for the idea! This could be the saving grace for me because I'm getting totally overwhelmed by the search for the right size wheels at decent prices!

[6ixSpd]

That is a massive difference in sidewall. Overall rotational diameter should not be more than 3% vs. stock.

Sounds like you'd be much better serviced a Lexus GS to be honest.

[Drivaar]

Thanks the6M3 -- but I've looked around at the options carefully and I really do think this is the best one to explore to balance cost and all the other needs. (Also, a Lexus GS is a much bigger car... the size of this one and every other aspect are good.