Anyone done an alloy wheel 'downsize'? All the discussions I read are for upsizing. That's for you young chickens. I'm just an old grump.

I've just decided to mount some older alloys that I have lying around on my 740T, but the wheels are 14-inch.

I want to end up with something a little wider than the original 195/60-15 tire size on the car (while also staying close to the original rolling diameter).

Should I be looking at something like 215/60-14, and more importantly, will there by any tire width issue?

Cheers,

Steve
'70 142s
'75 164e
'86 740T
and two dead Mercedes

Do you have a Mercedes Diesel about 1985 with 5 cyl diesel?
Thanks
Peter (just an old rooster)

First off, let me give you two websites that will help you immensely when trying to select tires for your car, and determining how far off you're going to put your spedometer.

http://www.eunos.com/tirecalc/
This site lets you enter 2 tire sizes and compare them, and tells you what percentage your spedometer will be off if changing from tire XXX to tire YYY.

http://www.dsm.org/tools/tiresize.htm
This is a handy calculator to explore all the possible equivalent sized tires for your stock size. Note: It works in 5% increments of the height, and the width is left un-rounded in milimeters. You will need to round the width up or down to the nearest standard mm increment and then use the first website mentioned above to find out how far off it will be from you standard tire size.

If I heard you correctly, the stock tire size (listed on the vehicle tire placard) is 185/65R15. Using the 2nd website listed, the direct equivalent possibilities in 14" tires are as follows:
For 50-series tires, you will want a tire that is 266 mm wide
For 55-series tires, you will want a tire that is 242 mm wide
For 60-series tires, you will want a tire that is 222 mm wide
For 65-series tires, you will want a tire that is 205 mm wide
For 70-series tires, you will want a tire that is 190 mm wide
For 75-series tires, you will want a tire that is 177 mm wide
For 80-series tires, you will want a tire that is 166 mm wide
For 85-series tires, you will want a tire that is 156 mm wide
For 90-series tires, you will want a tire that is 148 mm wide

The 205/65/R14 size tires are exactly the same size as your stock tire, except in a 14" wheel. If you wanted to go wider, try the 222/60/R14. -But since nobody makes a 222 size, round up to to 225/60/R14 and then use the tire calculator on the first website to find out how much your spedometer will be off. (compare Stock: 185/65R15 to new size: 225/60/R14) The tire calculator says that you'll be off by 0.7%, which is not much and easily acceptable. (When your spedometer indicates you're traveling 60 mph, your actual speed is 60.4 mph).

I hope this helps in your search for equivalent sized tires. Good luck and God bless,
Fitz Fitzgerald.
--
'87 Blue 245, NA 214K

I'm just a young chicken here trying to peck up some scraps. What are you doing with your old turbo wheels? I am looking to replace a bent draco wheel...

J. Studer

Well, I'm in Kanada and if you are in the US, frankly I'm not sure the extra shipping costs would make it worthwhile.

If there is anyone tuned in who lives in the Toronto-Ottawa-Montreal corridor, who wants a crack at my used wheels, drop me a line at steve.macsween@sympatico.ca (I say this as pickup will be MUCH easier than shipping),

I have a complee set but one would not hold its bead on the Nokias I had on for winter tires. I am now running a steel rim instead.

Steve

if you want to keep the rolling circumference close:

215-60/14
205-65/14

What do you gain? Not much.

From one old phart to another,
The circumference of the 195/60-15 is 1931 mm, and 1926 mm for the 215/60-14. Close enough. Will they fit in the wheel wells? Sorry, can't answer that one.

Erling.
--
My 240 Page

Earling, while the numbers you quoted are true, it's not quite the full story.

If I'm not mistaken, stock tire size is 185/65 15 which has a circumference of 1952.5.

Compared to that, 195/60 15 is 1932.0, so it's still within acceptable size.

And certainly, by comparing it to 195/60 15, the size of 215/60 14 still looks okay since it's 1927.7.

But comparing it back to the original size reveals that it's a 24.8mm difference. Not that that isn't still within tolerable ranges, but I just thought I'd make it a point that it's important to compare a new tire size to the original stock size, not what you have at the moment. It's easy for the error to add up otherwise. :-)

Anyway, I would get 205/65 14's.
--
Kenric Tam
1990 Volvo 740 base sedan (B230F)
My Volvo 'Project'

>> Anyway, I would get 205/65 14's.
\
So would I, but that size appears to be unobtainium (at least in the price/speed rating range in which I am looking).

Steve
--

dont know if this will help you any, but the 740 N/A ( GL GLE ) models came with 14 inch wheels, you are supposed to be able to go to 215 with the 14 inch but i personally havent tried it only inquired about it. i prefer the 15 in wheels in the 205 size found better control with them, the 14 were pretty crappy at high speeds, my size is 205/60/15 i replaced my rins with the Turbo rims as they also handled better.