I discovered today that m 240D has aluminum wheels. What's the big deal with them? Are they supposed to offer some advantage over the regular steel ones? I really can't see the point myself, though it does make changing tires a lot easier.

- Peter.

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2021 Chevrolet Spark
Formerly...
2000 GMC Sonoma
1981 240D 4spd stick. 347000 miles. Deceased Feb 14 2021
2002 Kia Rio. Worst crap on four wheels
1981 240D 4spd stick. 389000 miles.
1984 123 200
1979 116 280S
1972 Cadillac Sedan DeVille
1971 108 280S

They are lighter, ergo will allow for after acceleration. On a 240D you need every ounce or weight savings you can get.

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2004 F150 4.6L -My Daily
2007 Volvo XC70 -Wife's Daily
1998 Ford F150 -Rear ended
1989 J-spec 420SEL -passed onto its new keeper
1982 BMW 733i -fixed and traded for the 420SEL
2003 Volvo V70 5 Speed -scrapped
1997 E290 Turbo Diesel Wagon -traded for above
1992 BMW 525i -traded in
1990 Silver 300TE -hated the M103
1985 Grey 380SE Diesel Conversion, 2.47 rear end, ABS -Sold, really should have kept this one
1979 Silver 300D "The Silver Slug" -Sold

Aluminum wheels reduce unsprung weight, or the inertia of the moving mass (wheel end). This will have no measurable change on acceleration nor braking on smooth pavement as it is not significant in the weight of the car, but it is significant in allowing the wheel to follow bumps in the road better, which translates to more traction for cornering and braking on rough pavement. There is also some improvement in heat dissipation from the brakes, but a 240D isn't exactly going to doing a lot of acceleration/braking/acceleration/braking cycling that will benefit from slightly improved brake cooling (not with stock power LOL).

So for handling on rough pavement the reduced mass is the key.

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Gone to the dark side

- Jeff

Babymog, Excellent answer.

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/showthread.php?t=156207&highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

Thanks, but the real answer is that not everybody with a 240D has them. That makes them extra cool!

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Gone to the dark side

- Jeff

They also pass for steel wheels when you're checking out at the pick and pull yards.

😆
That's really all that there is to it.

to expand on babymog's excellent response, increasing the ratio of the sprung to unsprung weight is a specific goal for tuning of running gear. with the help of some numbers from our friend Stretch, i determined that this swap increased my ratio from 6.0 to 6.8. when i first made the swap i did think the wheels were dancing on the pavement a bit more ably. now i don't remember how it felt before, but there is a theoretical basis for making the mod.

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'77 240D, 504H, OM617.952, etc.

So it's supposed to feel better when driving? Frankly mine feels rather crappy. Of course that could be just my wore out suspension.

- Peter.

__________________
2021 Chevrolet Spark
Formerly...
2000 GMC Sonoma
1981 240D 4spd stick. 347000 miles. Deceased Feb 14 2021
2002 Kia Rio. Worst crap on four wheels
1981 240D 4spd stick. 389000 miles.
1984 123 200
1979 116 280S
1972 Cadillac Sedan DeVille
1971 108 280S

Less unsprung weight improves ride noticeably too. It'll also help with acceleration and deceleration but that would be tough to notice.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Steel wheels make a slow car slower.

The aluminum wheel is about 1/2 of what the steel wheel weighs.

Aluminum about 9.5 lbs
Steel around 18 lbs.

Give or take, been a while since I weighed them.

240D has the 5.5 inch wide wheel while the 300D used the 6 inch wide wheel.

The SL Pagoda guys are always looking for these wheels.

On E-bay these things go for a good price.


Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

The inertia has to have an effect on braking. Lots of people who run dubs note a measurable increase in braking distance. It might take a 240D to notice the effect on acceleration

Sixto
83 300SD

The 240 feels best and most lively with the light wheels. Big heavy wheels really load a car down...especially noticable with low powered cars like a 240. With the light wheels and correct factory sized tires a 240 rides buttery and handles nicely.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Big deal?

There's no big deal they're just lush - that's all!

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!