Factory shock lifespan

oranga · 05-25-2019, 10:47 AM

I’m planning on upgrading to a set of coil overs in the near future, but my frugal dad-ness can’t bring myself to get rid of my stock suspension before they need to be replaced. I’ve read before that 50k mi was a good rule of thumb, but what kind of mileage are other people getting out of their suspension?

mbanks21 · 05-25-2019, 11:14 AM

On average I'd say 50-60k is a good replacement time

cfm56d7b · 05-25-2019, 03:52 PM

Quote:

Originally Posted by mbanks21

On average I'd say 50-60k is a good replacement time

That's about right. It's not uncommon to see OEM shocks last 70K miles on smoother roads. After 50K miles, replacing both springs and shocks would be prudent (if moving forward with OEM replacement choices).

Machinebuilder · 05-25-2019, 05:44 PM

I think it can vary a lot based quality of roads you drive, how aggressive and attentive to potholes etc you are, wheel diameter and sidewall thickness and type of suspension your car has. Alot of base model cars with standard wheels and smaller lighter engines can go to 100,000 without problems. Sporty models don't do as well.

Polo08816 · 05-25-2019, 06:58 PM

Quote:

Originally Posted by Machinebuilder

I think it can vary a lot based quality of roads you drive, how aggressive and attentive to potholes etc you are, wheel diameter and sidewall thickness and type of suspension your car has. Alot of base model cars with standard wheels and smaller lighter engines can go to 100,000 without problems. Sporty models don't do as well.

I went about 75,000 miles before I replaced my M Sport suspension (passive 704 sport suspension) with the M Performance Suspension. I still have the M Sport (passive 704 sport suspension) in the basement just in case. I believe it was still okay with usable life.

AshlandTE87 · 05-26-2019, 08:41 AM

Quote:

Originally Posted by Polo08816

Quote:

Originally Posted by Machinebuilder

I think it can vary a lot based quality of roads you drive, how aggressive and attentive to potholes etc you are, wheel diameter and sidewall thickness and type of suspension your car has. Alot of base model cars with standard wheels and smaller lighter engines can go to 100,000 without problems. Sporty models don't do as well.

I went about 75,000 miles before I replaced my M Sport suspension (passive 704 sport suspension) with the M Performance Suspension. I still have the M Sport (passive 704 sport suspension) in the basement just in case. I believe it was still okay with usable life.

How would you compare the M Perf upgrade vs the passive 704 suspension? Vast improvement and how much did it lower your car? Iâ€™m considering this exact upgrade as I also have the passive 704 upgrade. This or combining M3 springs with B8â€™s.

Polo08816 · 05-26-2019, 09:51 AM

Quote:

Originally Posted by AshlandTE87

How would you compare the M Perf upgrade vs the passive 704 suspension? Vast improvement and how much did it lower your car? Iâ€™m considering this exact upgrade as I also have the passive 704 upgrade. This or combining M3 springs with B8â€™s.

It's definitely noticeable. Lowers the car by approximately 10mm so it's a very mild drop which is excellent for daily driving.

One huge advantage of the M Performance Suspension is that the kit comes with almost all the hardware to make this a 2 part DIY. You can assemble the suspension on 1 day and replace/install on another day. Minimal re-use of existing worn components.

FaRKle! · 05-26-2019, 11:40 PM

The M-Perf springs are much stiffer than M-Sport. They're even stiffer than M3/4 springs.

Polo08816 · 05-27-2019, 02:26 PM

Quote:

Originally Posted by FaRKle!

The M-Perf springs are much stiffer than M-Sport. They're even stiffer than M3/4 springs.

I doubt this.... is there literature from BMW supporting this?

FaRKle! · 05-27-2019, 03:10 PM

Quote:

Originally Posted by Polo08816

I doubt this.... is there literature from BMW supporting this?

Yes, there's official documentation that shows the spring rates. The 335/340i M-perf front spring is 12% stiffer than F8x ZCP front, and the rear springs basically have the same rate (except that the ZCP one is progressive).

Polo08816 · 05-27-2019, 03:32 PM

Quote:

Originally Posted by FaRKle!

Yes, there's official documentation that shows the spring rates. The 335/340i M-perf front spring is 12% stiffer than F8x ZCP front, and the rear springs basically have the same rate (except that the ZCP one is progressive).

I'd be interested in seeing this. Are you sure you are not confusing the M Performance Suspension (KW coilovers) for the F80 M3 versus the M Performance Suspension for the F30 RWD chassis?

FaRKle! · 05-27-2019, 03:44 PM

Quote:

Originally Posted by Polo08816

I'd be interested in seeing this. Are you sure you are not confusing the M Performance Suspension (KW coilovers) for the F80 M3 versus the M Performance Suspension for the F30 RWD chassis?

I'm quite sure it was the M-Perf suspension for the 335/340i because the PNs (31 33 6 860 631 front, 33 53 6 860 621 rear) are readily visible on the BMW ETK under options code SZP5A. I actually purchased the rear spring from that kit for my setup (and it was red like the M-perf springs).

I can't share the document with you unfortunately because I didn't see it online.

gameson · 08-01-2021, 09:04 AM

Quote:

Originally Posted by Polo08816

I went about 75,000 miles before I replaced my M Sport suspension (passive 704 sport suspension) with the M Performance Suspension. I still have the M Sport (passive 704 sport suspension) in the basement just in case. I believe it was still okay with usable life.

Where to buy m perf susp? And what’s the price? Thanks

sjreid · 08-02-2021, 02:09 PM

You'd be unlucky if they needed doing after 50k...

Many cars will get to 100k nowadays on originals but depends on lots of factors and driving styles obviously...

casualDIYer · 08-02-2021, 11:34 PM

Quote:

Originally Posted by oranga

I’m planning on upgrading to a set of coil overs in the near future, but my frugal dad-ness can’t bring myself to get rid of my stock suspension before they need to be replaced. I’ve read before that 50k mi was a good rule of thumb, but what kind of mileage are other people getting out of their suspension?

50k miles sounds right. Twin tube shocks (as used in the OE suspension) have a design that uses a gasket that wears over time. As the shocks are used, performance begins to degrade. Is that a failure? Perhaps not in the sense that the shock has completely failed but in the sense the original performance is now degraded. After 50k miles it doesn't perform as well as it did at 10, 20, or 30k. A monotube design in comparison, generally, has a longer lifespan of consistent performance.

Bdub440i · 08-03-2021, 08:39 AM

Mine were on the way out at 40k. I could press them down with my hand and they were slow to return. Never bothered me or caused any problems while on the car though.

hollovoid7 · 08-03-2021, 10:17 AM

I replaced my rear and fronts at 90,000 and they were absolutely trashed. Rears took 3-4 mins to rebound (seriously, I timed it) new ones 2 seconds.

Fronts were harder to tell, but you did have to pull them out the rest of the way. I almost thought my b6 replacements were too long because of that.

05-25-2019, 10:47 AM	#1
oranga Second Lieutenant 87 Rep 221 Posts Drives: 335 6mt Join Date: Feb 2018 Location: Houston iTrader: (4)	Factory shock lifespan I’m planning on upgrading to a set of coil overs in the near future, but my frugal dad-ness can’t bring myself to get rid of my stock suspension before they need to be replaced. I’ve read before that 50k mi was a good rule of thumb, but what kind of mileage are other people getting out of their suspension?
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05-25-2019, 11:14 AM	#2
mbanks21 Colonel 1268 Rep 2,957 Posts Drives: 2015 335i MSport Join Date: Aug 2013 Location: High Bridge, NJ iTrader: (8)	On average I'd say 50-60k is a good replacement time __________________ 2015 335i Msport/6 JB4/EWG/E30/VRSF DP/ER CP/ VRSF Race Exhaust/ Injen Intake/Verde Axis 19x8.5/9.5 245/35/275/30 Conti Extreme CS/ H&R Sports / Motorsport Hardware Stud Conversion
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05-25-2019, 05:44 PM	#4
Machinebuilder Second Lieutenant 279 Rep 268 Posts Drives: 640 IX GT Join Date: Feb 2014 Location: Northeast USA iTrader: (0)	I think it can vary a lot based quality of roads you drive, how aggressive and attentive to potholes etc you are, wheel diameter and sidewall thickness and type of suspension your car has. Alot of base model cars with standard wheels and smaller lighter engines can go to 100,000 without problems. Sporty models don't do as well.
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05-26-2019, 11:40 PM	#8
FaRKle! Brigadier General 4016 Rep 3,539 Posts Drives: 328d Wagon, M2 Comp, i4 eD35 Join Date: Sep 2016 Location: Bay Area, CA iTrader: (4) Garage List 2023 BMW i4 eDrive 35 [0.00] 2017 BMW 328dx Wagon [0.00] 2021 BMW M2 Competi ... [0.00]	The M-Perf springs are much stiffer than M-Sport. They're even stiffer than M3/4 springs. __________________ -328d Wagon Build Log (with helpful reference links) -My YouTube Channel for some of the best DIYs and in depth information Please don't PM me for suspension recommendations unless interested in paid private consultations.
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08-02-2021, 02:09 PM	#14
sjreid New Member 2 Rep 5 Posts Drives: BMW 2016 318i Touring F31 LCI Join Date: Aug 2021 Location: UK iTrader: (0)	You'd be unlucky if they needed doing after 50k... Many cars will get to 100k nowadays on originals but depends on lots of factors and driving styles obviously...
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08-03-2021, 08:39 AM	#16
Bdub440i Enlisted Member 14 Rep 42 Posts Drives: BMW 440i Join Date: May 2021 Location: Cincinnati iTrader: (0)	Mine were on the way out at 40k. I could press them down with my hand and they were slow to return. Never bothered me or caused any problems while on the car though.
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08-03-2021, 10:17 AM	#17
hollovoid7 Private 47 Rep 99 Posts Drives: 2016 BMW 428xi Gran Coupe Join Date: Jun 2019 Location: Lyons NY iTrader: (1)	I replaced my rear and fronts at 90,000 and they were absolutely trashed. Rears took 3-4 mins to rebound (seriously, I timed it) new ones 2 seconds. Fronts were harder to tell, but you did have to pull them out the rest of the way. I almost thought my b6 replacements were too long because of that.
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