[dietMcar]

-So i’ve done a decent amount of research and still can’t decide what to do.

My wheels are 18x8.5 +35 squared. i cheaped out on tires for them and quickly realized i want to get different ones and also try a different size. the ones that were recommended and put on are 225/40/18. i feel like it’s drastically worse handling wise and much more harsh. Does anyone have any thoughts on what size/brand i should go with next?

In addition to this, the car is at 97k miles and i feel like the shocks and struts could probably be replaced to help as well. what would you guys recommend going with? as i said before it is xdrive and does have EDC. it’s pretty much a daily, i don’t want to go super low but i do want to get rid of some gap while also keeping ride quality in mind. i also can’t quite afford to get the absolute best of the best coilovers at the moment.

-Any advice is much appreciated, i’ve been trying to figure out what to do for months 😅

[alohasurftoad]

Tire sizes 235/45/18, 245/40/18 or 255/40/18

Eibach pro-kit '5-22 springs over Koni SA dampers w/F80 bumpstops and EDC coded out. Change strutmounts, spring seats and dust boots as well.

[jmanB45]

What aloha said. As for tires, can't go wrong with Michelin or Continental. I've personally found Continental to have a relatively softer sidewall and ride great while offering decent grip. (ExtremeContact DW and DWS06+)

[johnung]

Originally Posted by dietMcar

-So i’ve done a decent amount of research and still can’t decide what to do.

My wheels are 18x8.5 +35 squared. i cheaped out on tires for them and quickly realized i want to get different ones and also try a different size. the ones that were recommended and put on are 225/40/18. i feel like it’s drastically worse handling wise and much more harsh. Does anyone have any thoughts on what size/brand i should go with next?

In addition to this, the car is at 97k miles and i feel like the shocks and struts could probably be replaced to help as well. what would you guys recommend going with? as i said before it is xdrive and does have EDC. it’s pretty much a daily, i don’t want to go super low but i do want to get rid of some gap while also keeping ride quality in mind. i also can’t quite afford to get the absolute best of the best coilovers at the moment.

-Any advice is much appreciated, i’ve been trying to figure out what to do for months 😅

I have the same size wheels and I have a square setup with 255/40-18. Highly recommend it for ride and handling. Exact same diameter as stoc 225/45-18 so no speedometer/odometer issues

[johnung]

For springs based on your requirements I recommend the Eibach -06 kit. It’s not as aggressive of a front drop as the -05 kit so it will ride better and clear steep driveways etc. They good perfectly with Adaptive/EDC suspension.

Not related to my recommendation, but I have a slightly used Eibach -06 set that I’m about to post for sale for $200. They are $350 new.

[johnung]

Photos show stock F30 XDrive springs vs Eibach -06 spring kit.

[dietMcar]

Originally Posted by johnung

I have the same size wheels and I have a square setup with 255/40-18. Highly recommend it for ride and handling. Exact same diameter as stoc 225/45-18 so no speedometer/odometer issues

any pictures of this setup? any rubbing?

[johnung]

Originally Posted by dietMcar

any pictures of this setup? any rubbing?

I’m driving so have to look for photos later. No rubbing with that wheel size and offset and tire size. Plenty of space! The in/out offset range is probably ET29-ET42 so ET35 is perfect

[johnung]

I’m a fan of the Adaptive/EDC suspension especially since you already made an expensive investment in it.

The dampers leak when they go bad so just replace that pair with Bilstein B4-Damptronic, or with Genuinw BMW (possibly made by Bilstein anyway) at a discount from GetBMWParts website.

[dietMcar]

Originally Posted by johnung

I’m a fan of the Adaptive/EDC suspension especially since you already made an expensive investment in it.

The dampers leak when they go bad so just replace that pair with Bilstein B4-Damptronic, or with Genuinw BMW (possibly made by Bilstein anyway) at a discount from GetBMWParts website.

if you can show me some pics of the setup you’re talking about i may be interested in the springs

[danb1979]

Originally Posted by dietMcar

-So i’ve done a decent amount of research and still can’t decide what to do.

My wheels are 18x8.5 +35 squared. i cheaped out on tires for them and quickly realized i want to get different ones and also try a different size. the ones that were recommended and put on are 225/40/18. i feel like it’s drastically worse handling wise and much more harsh. Does anyone have any thoughts on what size/brand i should go with next?

In addition to this, the car is at 97k miles and i feel like the shocks and struts could probably be replaced to help as well. what would you guys recommend going with? as i said before it is xdrive and does have EDC. it’s pretty much a daily, i don’t want to go super low but i do want to get rid of some gap while also keeping ride quality in mind. i also can’t quite afford to get the absolute best of the best coilovers at the moment.

-Any advice is much appreciated, i’ve been trying to figure out what to do for months ��

Agree with alohasurftoad - you need 245/40 min on those alloys

I run 235/45/18s on my 18x8 405Ms (Goodyear Assym 6s as summer tyres) and 397s (Goodyear all-seasons as winters), to avoid the OEM 225/45 size as it's slightly stretched and not the best width IMO

I've also just fitted Bilstein B4S shocks and Eibach pro-kit springs to my F31; pic as below so you can see the tyres and ride height etc; it's much, much better now!

[johnung]

Originally Posted by dietMcar

if you can show me some pics of the setup you’re talking about i may be interested in the springs

I’ll go through my photos. I’ve had 225/45-18, 245/40-18 & 255/40-18 on my car.

245/40 are about 25.7” which is slightly less than stock 26.0”. They handle great downsides are speedometer at highway speeds will read ~1-2mph more than car is actually going. Slightly more tire/fender gap, slightly less comfort.

255/40-18 are my preference. Exactly same stock 26.0” diameter. Great handling and fitment.

Since you are in Ohio I assume that you prefer performance all season tires vs summer tires. Two that I would recommend are:
Michelin Pilot Sport AS4
Continental DWS06+

[dietMcar]

Originally Posted by johnung

I’ll go through my photos. I’ve had 225/45-18, 245/40-18 & 255/40-18 on my car.

245/40 are about 25.7” which is slightly less than stock 26.0”. They handle great downsides are speedometer at highway speeds will read ~1-2mph more than car is actually going. Slightly more tire/fender gap, slightly less comfort.

255/40-18 are my preference. Exactly same stock 26.0” diameter. Great handling and fitment.

Since you are in Ohio I assume that you prefer performance all season tires vs summer tires. Two that I would recommend are:
Michelin Pilot Sport AS4
Continental DWS06+

yep, i think im going to go with the 255/40’s. seems like it would make the most sense for me. i really appreciate the good info 🫡

[dietMcar]

Originally Posted by danb1979

Agree with alohasurftoad - you need 245/40 min on those alloys

I run 235/45/18s on my 18x8 405Ms (Goodyear Assym 6s as summer tyres) and 397s (Goodyear all-seasons as winters), to avoid the OEM 225/435/ size as it's slightly stretched and not the best width IMO

I've also just fitted Bilstein B4S shocks and Eibach pro-kit springs to my F31; pic as below so you can see the tyres and ride height etc; it's much, much better now!

[img]https://i.postimg.cc/zXt6msDQ/backonthedrive2.jpg[/img]
[img]https://i.postimg.cc/dttpxsFd/backonthedrive1.jpg[/img]

this looks really good. how much did the shocks and springs and everything run you? do you have edc as well?

[danb1979]

Originally Posted by dietMcar

this looks really good. how much did the shocks and springs and everything run you? do you have edc as well?

No; it's RWD and non adaptive, exactly the spec I wanted when I was looking at F31s

Having owned an F01 with adaptive suspension before; it's not something I was keen on getting again & I've no need for xDrive

The Bilstein B4S shocks (correct ones for the M Sport F31s) were c£100 rears and £110 fronts from Autodoc in Germany; the Eibach pro kit springs were c£150 IIRC - all UK Sterling obviously

I fitted new Sachs top mounts all round with all new OEM BMW gaskets, spring perches, bump stops and dust boots etc... OEM F31 bump stops are fine; no need for shorted M3/M4 ones as the Eibach springs only lower 10-15mm max over OEM M Sport

I've just had a week away in the Highlands in Scotland and the car was rammed to the rafters there & back and the car never bottomed out once and I hit some rotten potholes/rough roaded areas as well...

[danb1979]

FYI dietMcar

Post 2516 here: https://f30.bimmerpost.com/forums/sh...29492&page=115

He's just fit ARC8s with 255/40 tyres and IMO; they're a touch too wide and they're 18x9 alloys

The tyres seem to bulge a bit too much for my personal tastes and that runs a big risk of rubbing when it comes to lowering the car

It's a personal preference; but 245/40s would work much better IMO - you'd get a straighter sidewall then (better rim protection, better turn in feel)

245s are a bit too wide for 18x8s IMO (that's why I went 235/45); but on 18x8.5; they'd be perfect...

Different tyres have different sidewall designs too; some are very straight, some are softer and bulge a bit more

Worth bearing in mind IMO

[jmanB45]

+1 for 245/40/18 being the sweet spot for 8.5 width wheels.

[dietMcar]

Originally Posted by alohasurftoad

Tire sizes 235/45/18, 245/40/18 or 255/40/18

Eibach pro-kit '5-22 springs over Koni SA dampers w/F80 bumpstops and EDC coded out. Change strutmounts, spring seats and dust boots as well.

are you aware of anywhere i can get EDC coded out? i haven’t done any research on that yet but i would be open to doing it

[alohasurftoad]

Originally Posted by dietMcar

are you aware of anywhere i can get EDC coded out? i haven’t done any research on that yet but i would be open to doing it

you'd have to get the obd plug in and coding tool such as esys, bimmercode, etc. or have the coding done for you. it seems you don't want to spend too much on stuff at this stage in your vehicles life, so i suggested the Koni SA dampers with Eibach Pro-Kit springs. a passive suspension that many here are quite happy with.

and if you do 245/40/18 you'll need to be lowered since the 25.7" dia would cause more gap at stock x-drive height. 235/45/18(26.3") would provide the least gap and comfiest ride, compromising a bit of grip due to narrower tread width. 255/40/18 will have the most grip and is probably what i'd run just to match the B58's torque. 245/40/18 would have the sharpest turn in and look the best on the 8.5".

[dietMcar]

Originally Posted by alohasurftoad

you'd have to get the obd plug in and coding tool such as esys, bimmercode, etc. or have the coding done for you. it seems you don't want to spend too much on stuff at this stage in your vehicles life, so i suggested the Koni SA dampers with Eibach Pro-Kit springs. a passive suspension that many here are quite happy with.

and if you do 245/40/18 you'll need to be lowered since the 25.7" dia would cause more gap at stock x-drive height. 235/45/18(26.3") would provide the least gap and comfiest ride, compromising a bit of grip due to narrower tread width. 255/40/18 will have the most grip and is probably what i'd run just to match the B58's torque. 245/40/18 would have the sharpest turn in and look the best on the 8.5".

appreciate the help 🙏🏼 i ended up ordering 245/40’s last night. we’ll see how they look and feel. maybe i’ll wish i would’ve got 255’s, but i think the 245’s will be much better than the 225’s on it now. now i need to look into the shocks and springs today

[danb1979]

Originally Posted by dietMcar

appreciate the help 🙏🏼 i ended up ordering 245/40’s last night. we’ll see how they look and feel. maybe i’ll wish i would’ve got 255’s, but i think the 245’s will be much better than the 225’s on it now. now i need to look into the shocks and springs today

The 245/40s will be perfect IMO

As for shocks and springs; you need to decide if you want firmer than OEM; as compliant as OEM (as close as you can get) or coilover levels etc...

I test drove an F30 330D with the Bilstein B12 kit (B8s with Eibach pro kit springs); for me is was far too firm for our local roads (superb on the tight/twisty country roads) but normal roads at normal speeds; just too bouncy

i also test drove an F31 340i on Bilstein B16s and again; just too firm (but bloody amazing on fast roads)!

I'm personally not a fan of Koni; had plenty of build quality issues with them in the past (but that's going back to late 2000s); I've had Bilstein shocks plenty of times with zero issues and now my F31s on the B4S shocks with the Eibach pro kit springs; it's absolutely spot on..

It took the pot hole ridden, super-rough roads in the Scottish Highlands with ease and the handling is much better too; however my suspension overhaul was full (ie every arm and more)!

Cost me a fair whack; but I wanted to future proof the car until at least mid 2025 as I've promised to keep it until we've paid our mortgage off

[dietMcar]

Originally Posted by danb1979

The 245/40s will be perfect IMO

As for shocks and springs; you need to decide if you want firmer than OEM; as compliant as OEM (as close as you can get) or coilover levels etc...

I test drove an F30 330D with the Bilstein B12 kit (B8s with Eibach pro kit springs); for me is was far too firm for our local roads (superb on the tight/twisty country roads) but normal roads at normal speeds; just too bouncy

i also test drove an F31 340i on Bilstein B16s and again; just too firm (but bloody amazing on fast roads)!

I'm personally not a fan of Koni; had plenty of build quality issues with them in the past (but that's going back to late 2000s); I've had Bilstein shocks plenty of times with zero issues and now my F31s on the B4S shocks with the Eibach pro kit springs; it's absolutely spot on..

It took the pot hole ridden, super-rough roads in the Scottish Highlands with ease and the handling is much better too; however my suspension overhaul was full (ie every arm and more)!

Cost me a fair whack; but I wanted to future proof the car until at least mid 2025 as I've promised to keep it until we've paid our mortgage off

understandable. i’ll be honest, im not too picky on what setup i can get at the moment on somewhat of a budget.. i would be open to coding out EDC if i can do it on my own and maybe going with the kw v1’s or something similar. or even bc coilovers if they are decent quality.

i’m trying to decide if coilovers are worth it considering all i’ll be doing is some spirited daily driving. if i did coilovers it would be on the cheaper side like the BC’s or something similar. it would make more sense to me to just get some lowering springs, but like i said the stock suspension has 97k on it so i feel like it’s time to do something..