2 Questions: Tire Sizes & Console Issue ('68 220)

[aircap]

Hey, folks:

I just bought a '68 220, and have been troubleshooting some little issues here and there. I have a couple questions you more experienced MB people might be able to help me with.

1) The tires on this car are shot...I have a spare set of 215/75R14 tires and wonder if they'll fit the Mercedes. I know the originals were 175 series, and the ones on there now are 195 series. Is this going to create a clearance problem? I'd sure like to be able to use the ones I've got and not buy a new set.

2) The console where the radio mounts does not want to stay in place because the ears where the knobs are supposed to tighten down are all chewed up. Short of finding another console, any ideas on how to keep it in place and/or repair the existing piece?

Thanks in advance, and happy new year to all!

Best regards,
Michael Carmody
Wichita, Kansas USA
Air Capital of the World

http://www.wichitavortex.com/images/68benz220-front.jpg
http://www.wichitavortex.com/images/68benz220-back.jpg

[t walgamuth]

i would say it is likely to be iffey.

i would probably mount one and put it on the front and drive around including going over big dips that bottom out the suspension and hard cornering. if that clears then i would try it on the back the same way.

but dont drive too far with different sized tires on the back cause you will heat up the gear lube.

good luck

tom w

[aircap]

Hey, Tom:

Thanks for the reply. It seems like it should be OK, as the current tires are 195/75R15s and appear to have plenty of free space around them.

By my (possibly erroneous) calculations, the 215s would be a total of 2cm taller, 1cm above the axle and one below; the width would also be 15mm wider. Of course, the issue is whether that little bit is just enough to cause a clearance problem.

I was hoping someone in here had already gone down this road, but I nonetheless appreciate your advice sincerely.

Best,
MC

[230/8]

Your 215 tires will result in the speedo registering approximately 6.7% slow; i.e at an indicated 60 mph you will be traveling 64 mph. So long as you have clearance, your decision to use the 215s should be a non-event. That said, run a measured mile check (or borrow a radar gun from a friendly cop) to check your speedo. Some MB speedos are inaccurate (commonly a bit fast), so your oversized tire just might make the speedo more accurate.

FYI: When you buy tires in the future, the 185/75 size is an exact size replacement for the original and hard to find or expensive to buy 175/80 size. The speedo registers normal and the overall size is so close that you cannot detect a visual difference.

230/8

[bluebenz]

I thought the original tire size was 185/75/14? I know many people use 195/70/14, as they are cheaper and easier to find and almost the same diameter!

Don't you think the 215 will result in slower acceleration?

[Mike D]

215's won't fit in the spare tire well. I don't think acceleration is a factor with a 220.

Steering will be different. Turning radius will be larger and will require a bit more effort at parking speeds.

[230/8]

MB280c: According to the technical data manual for these cars the original size was/is 175. I still have the original spare for my 114, and it is a 175/80. The standard cross section ratio was 80 at that time. Modern tires are currently available in 75 series cross section which means that a 185/75 tire has the same rolling diameter as a 175/80 tire. The 185 tire is approximately 3/8 inch wider than the original 175 tire. You can get 80 series tires from specialists like Coker, but you will pay dearly.

The larger tire will result in an approximate 6.3% reduction in effective gear ratio which corresponds to a reduction in mechanical advantage of the same amount; i.e. yes, the car will be a bit less responsive leaving from a stop, but hey, it's a 220, who will notice?

aircap: If I correctly understand your console problem, it may possibly be fixed so it will securely hold the radio. Try fabricating a thin aluminum or steel reinforcement collar and expoxying it to the back side of the console opening. Your Becker has an aluminum frame attached to it which uses the "ears" you refer to to pinch the frame against the console face from the rear. The face plate snaps to this frame after the radio chassis is screwed in tight to the console.

Just glue a thin aluminum or steel reinforcing collar to the inside of the console opening to take the place of the chewed off portion of the console. Your radio chassis frame is good to make the pattern and get the opening sized properly. You want to make the collar so it completely surrounds to radio frame so everything will fit snug and not move about.

If the chewed area extends beyond the edge of the radio face plate then you will need to replace the console to get a good appearance, if that is important to you.

Hope this makes sense...

230/8

[t walgamuth]

Originally Posted by Mike D

215's won't fit in the spare tire well. I don't think acceleration is a factor with a 220.

Steering will be different. Turning radius will be larger and will require a bit more effort at parking speeds.

i agree with everything except cannot see how it will increase the turning radius.

tom w

[aircap]

Wow, you guys...thanks for all the information! I put the 215s on today and the car rides amazingly better (though the old tires were cracked and underinflated, so it's not a huge surprise). Clearance does not appear to be an issue...but when I go to replace these I will revert to a more traditional size. (I had this set leftover from my old 1961 Thunderbird.)

Anyway, thanks again. I appreciate the time you all have taken to help me out. Oh, and I've just posted a new message regarding my heater. Feel free to weigh in on that issue, too, if you're so inclined.

Best regards as always,
MC