I am now the proud owner of a 63 plate R172 250 CDI and am loving it! I have the following plans for the car, any advice or input would be highly appreciated.
Upgrade the lights to HID/Xenon
Retrofit the airguide deflectors (if possible)
Remap engine & Install aftermarket air filter
Tint rear windows
Install becker module
When i went to pick up the car the air conditioning was stuck hot! apparently this is a known fault with the car and under and its being sorted out under warranty. Are there any other known faults or anything that I should be aware of with my type of car? Any assistance on this would be highly appreciated also.
Looking forward to your replies and hello all
Hi from the wilds of Somerset!
I have to be honest, in 3 years on these forums I've not come across a heater stuck on hot. It may be a known fault to the folks who sold you the car though
As you've probably noticed, the halogen headlamps are SHOCKING, but there is a range adjustment that helps massively.
Air guides are easy to retrofit, but they're not a lot better than the fabric wind stop and the parts are ludicrously expensive new (about £700) and in 3 years I've never seen a set for sale on eBay. Even the black roll bar covers are very, very rare. The alternative is something called a WindRestrictor which is a plexiglas panel that fits in between the roll bar covers like the mesh panel but solid. That works well. There is also a German plexiglas panel on eBay that does the same job but is a bit cheaper.
The aftermarket air filter is utterly pointless as it gets you no more power. If you want it for the sound it makes then maybe it's worth it but exhausts and air filters don't get you a lot tuning the OM651 motor.
Remaps are surprising uncommon, although a lot of CDi 250s are leased from new as company cars so maybe the scope to remap isn't really there. Tuning boxes are plentiful though - DTUKs has a decent reputation and probably won't blow up your engine. If you want a remap, GAD seem to have the highest headline claim at 280 bhp and 625Nm torque but they haven't actually published a rolling road printout and they claim a 75bhp uplift from 204bhp which makes their maths and their ability to tell PS from bhp a bit suspect! (The standard SLK is 204PS which is 201bhp).
Mercedes Remapping Mercedes 250 CDI Remapping
Tinting the rear windows is also not something widely discussed on here, the Becker units are cheap and plentiful on eBay and the badges practically fall off themselves if you so much as show them a heatgun and a bit of dental floss.
Given the year of your car, you may also be lucky and find that you have a clear glass roof hidden behind the solid roof panel, I which case you can literally pull the solid panel off and press-fit one with a hole in it's place. That's a £190 retrofit for a £1000 option that Mercedes unsurprisingly stopped in late 2014 when they put a bit of black felt on the roof window.
As for other faults, there are loads of people reporting what I would call post-warranty quality issues ie. The car seems to have built with a 3-year life in mind and after that anything and everything can and does fail, but I'm not aware of anything that always fails. And the fundamental drive-train seems robust enough.
Unless you've bought a Fire Opal red car. In which case be prepared to notice tiny bubbles in the paint for which Mercedes will do a free back to the metal respray. Other colours are fine.
Finally, as someone who was belatedly converted to the joys of the SmartTop, get a SmartTop. It lets you drop or raise the roof from outside the car. Suddenly, the thing you can't ever see (putting the roof up or down) becomes a joy you too can appreciate. It also lets you get in or out of the the car with the roof down then put it up afterwards. That might not sound like much but in tight car parking spaces it makes getting in and out massively easier. Plus it also lets you put the roof up or down while the car is moving which I'm still not 100% happy about although everyone else tells me it's fine.
Enjoy your new car. They're really good!