Tires for my 1984 300CD - PeachParts Mercedes-Benz Forum

rcounts · #1 08-10-2010, 02:24 AM

Will 225-60-14's fit without rubbing?
The diameter calculates out to 24.62" versus the stock 195-70-14 diameter of 24.74"

So the speedo ought to be pretty much spot on, but I'm wondering if being 30mm wider (roughly 1-1/4") is going to cause any problems.

Anybody running this size or ever even tried them? Costco has BFG Radial TAs in this size for $89 each.

layback40 · #2 08-10-2010, 05:03 AM

I have 215/65-14's on my 300D. I have non Mercedes rims (ford), they fitted and I had a set. The standard 5 1/2 " rims were not wide enough for the wider tires.
My tires are maybe 1/2" bigger in diameter than the standard ones were, I put them side by side. Thats only the difference between new & old tires. If the 225's fit go for it.
My biggest concern would be them rubbing on the inside of the wheel well on the front when on full lock.
Hopefully some one will tune in who has done it.
What do they guys at tire rack on here think of the size change?

willy2004 · #3 08-10-2010, 05:11 AM

seriously, just buy something cheap - it aint no race car
I used to get Dunlops from Sears for $40/piece back when i had a 126

ImBroke · #4 08-10-2010, 05:49 PM

Quote:

Originally Posted by willy2004

seriously, just buy something cheap

Really? The only thing between you and the road are 4 patches of tire. I don't cheap out on tires, but that's just me.

andrewjtx · #5 08-10-2010, 06:18 PM

I just bought some Kumho's from TireRack in the stock 195/70-14.

So far they feel pretty good on hot dry pavement. We'll see what they do when we get some rain come fall.

rcounts · #6 08-11-2010, 12:36 AM

Quote:

Originally Posted by layback40

I have 215/65-14's on my 300D. I have non Mercedes rims (ford), they fitted and I had a set. The standard 5 1/2 " rims were not wide enough for the wider tires...

Ford rims, huh? Off of what model Ford? I didn't know they made anything with a 5 on 112mm bolt pattern...

Renntag · #7 08-11-2010, 01:46 AM

Just ordered tires one size larger for my W123 from Tire Rack. I dont remember the size off hand. If the numbers look like the larger tires you want to try will work, go for it. Be sure to get quality pieces.

I am also curious what ford has 5 on 112 and what the offset was.

79Mercy · #8 08-11-2010, 01:54 AM

Well ford doesn't have a 5x112 rim, however they do have a 5x114 rim which does fit kinda tight. haha, a friend of mine had these laying his garage around so we mounted them to the 300D for fun.

Renntag · #9 08-11-2010, 02:13 AM

Ok, so you were able to weasel a set of wheels onto the car. how badly does it vibrate at highway speeds? What is the difference in hub size?

It doesnt look to bad.

79Mercy · #10 08-11-2010, 02:17 AM

It didn't vibrate, however it didn't feel very stable. I believe those are 5x114.

t walgamuth · #11 08-11-2010, 06:01 AM

Using wrong hole pattern is a very bad idea. Especially with an alloy rim. You are asking for a failure.

I don't know from experience but I imagine the 225/60s will fit. I run 225/50s on my Miata with a 6" rim. At full lock they rub the sway bar.

For my street tires on the benzo I always use Michelin. I have tried other brands but always come back to michelin. I am running hydroedges now.

layback40 · #12 08-11-2010, 08:47 AM

I think they may be the 114mm. They are steel rims of an Australian ford falcon. Dont know if that is of any use. the holes in the rims are about 1/2mm off line, but doing the bolts up properly results in them centered fine. No vibrations.

t walgamuth · #13 08-11-2010, 09:22 AM

They will work loose and structurally they are not designed for a point load on the lugs but for a load distributed around the entire lug/wheel contact.

Zerohour3k · #14 08-11-2010, 09:28 AM

I bought a set of General Altimax RT's in a 205-70-R14 size, for my '83 300D. Love them so far... they handle fairly well in the rain or snow, and really bite the pavement in dry conditions. Plus they have a much higher load rating than most other tires available for that size, which is important for such a heavy car.

Check on TireRack.com, they were pretty affordable.

rcounts · #15 08-11-2010, 11:55 AM

OK, now I see. Ford made lots of vehicles with the 5 on 114.3mm bolt pattern. FYI, 114.3mm is a 4-1/2" bolt circle.

As others have said, putting a wheel with a 114.3mm bolt circle on a vehicle with a 112mm bolt pattern is a very BAD idea. 2.3mm is just under 1/10th of an inch. May not sound like much but as others have pointed out it puts a heavy side-load on the lug bolts (trying to bend them outwards) instead of an even load around the entire head of the bolt. In engineering terms the bolts are designed to handle a lot of shearing load, but NOT a lot of deflection (bending sideways) load.

Ever notice how the underside of the head on lug nuts and lug bolts are tapered - and the hole in the wheel is tapered to match? That is so that the load can be spread over a bigger surface - both larger in diameter AND more surface to surface contact between the wheel and the head of the bolt. They are engineered this way to add strength, center the bolt in the hole, and provide a larger contact area (more friction) between the wheel and bolt head to help keep them tight. Putting the tapered fastener into the tapered hole off-center defeats all those positive objectives.

I've done this on an off-road only vehicle that travels at relatively low speeds, but I wouldn't even consider doing it on a vehicle being driven on the street. The speeds, forces, and stakes are just too high for it to be a good idea.

Just my 2 cents...