tire size increase
 

Hi,

I have a 300D and would liek to know if anyone has done a tire width increase in their car. To go from 195 70R14 to 205 65R14 causes an overall tire diameter difference of about .3 inch calculated using the following equation: (2*(195*.7)+14) all units converted correctly for both. Will I see any appreciable handling/traction differences in increasing the witdth, and perhaps more importantly, will I see any appreciable fuel economy drops? Thanks

JMH

The closest size, which Id think Id choose anyway would be 225 60HR14. Somethign like an HR rated Michelin Pilot.

Im probably best off sticking with Dunlop SP sport A2's for their AA traction, A temp and H speed rating, and low price, in the stock size, arent I? After all, Im driving a 20 year old diesel car...

JMH

Will all those sizes that you mentioned fit on that 14in. wheel?

Alex

Diesel head

Sure, that is what the 14 in the size means. Whether it will fit in your wheel-well is another thing.

JHZR2
You shoud check to see if it hits any suspension parts when turned and bounced up and down.
I don't really care for the 60 series tires as compared to 70 series.
With the 60 series, the steering loses some of its tracking ability. This is what I love about the 123, is that relaxing straight ahead stability. When you go to a wider tire, there is less of this.
I will agree that your upsize is correct and a very common one and you will be more than happy with it.
I think that there are many more options in the 60 series size than the 70, and you can explore more performance oriented models for your Benz. Keep us updated with your final choice.

In general, the more rubber you put on the road, the more traction you will get, but some brands will be better than others.

But there are few absolutes in tires;
A sticky 70 will get better traction than a high mileage compound 60, for instance.

AND OR, a high mileage 60 may have less rolling resistance than a sticky 70.

AND OR, a sticky Yokohama or Michelin 70 will out perform a 60 series Goodyear cheapy.

I hope you see where I am going with this. There is so much to this tire business that there are no quick and easy answers to so many different questions. The Tirerack website makes for fascinating reading and shows you how many variables there are.

I remember reading one report about a certain brand of tire in a 225/60/15 size, made in this companies Brazilian plant, completely sucked when tested in the rain, but was acceptable in the dry. The same size example, same brand, etc. BUT made in their French factory, was so superior in the rain and other conditions, that the testers felt that it was actually a different tire model altogether! It wasn't though, and the test report went on to explain the same thing, that there were few absolutes in recomending tires.

Unfortunately this makes things very confusing for the public, and affords the advertising people much leeway in what they say about a tires merits.

FWIW dept.
I just put a pair of Dunlop D60 A2's on the front of my CD, which replaced a pair of Hankooks which were in good shape still. Much better tracking, and much less road noise (none).

So a 205 or 225 width will fit on those wheels? I have the stock size 195 70HR/14 tires (bridgestone) because the tire guy said my wheels couldn't accomodate any other size.

Alex

I was kicking around the 205/65 bump from the 195/70 and I tell you, I liked the original setup. Maybe its my sensitive eye, but I thought the car looked too high with too much tire with the modified tire size, so I stuck with the original set-up. Keep in mind, engineers go through months of testing when designing a car for tires and I would stick with what they offered, for there must be a reason. I mean, if the larger tires were an option, that's one thing, but you wouldn't want to mess with anything, especially in a new car with ABS, traction control and ESP computers. You are asking for problems messing with the newer cars, but on a 300D, its personal pref. I wound up with the AVON CR 338s, and I must say, they are the best tires I've ever owned, turning what was an elephant with roller skates to a track runner with Nikes. Good luck!

need a wheel of width 7 inches minimun to accomodate a 225 cross section tire. reduce by 1/4 to 1/2 inch required wheel width for each 10mm reduction in tire crossection.

Check out this tire size calculator I found:

http://www.miata.net/garage/tirecalc.html

Your proposed change wouldn't make much of difference in fuel economy. Your car would be going 1% slow than your speedometer would be reading.

I'm running original size tires on the 240D and 205/75/14 on the 300D. I like the way the original feels better.

I'm running Yokohama Avid H4's in the stock size (195/70/R14)



They are a VERY good set of tires that seem to fit my 300D nicely. The tread is also aggressive looking, kinda funny on an old Diesel :D


I paid about $300 for the tires and having them mounted.

I run 205/70/14's
 

I put a set of 205/70/14's, Yokahama Avid T-4, on my 85 300D. This tire is a performance tire rated equivalent to a touring tire for quietness and ride smoothness. The differences between 195/70/14's and these are subtle:

1) softer ride on this bigger tire, (I put on new Bilstien comfort shocks, and wanted to maximize soft comfortable ride).
2) steering "heavier", car wanders a little more on highway.
3) tires leave marks on the guide rods when steering to the limit;
4) essentially no difference in fuel economy
5) probably better dry road traction due to greater surface contact, but probably more hydroplaning potential on wet roads;
6) The car stands higher off the road....I like this as I often drive on dirt roads when I go fishing. I also like the look.


All in all, Im getting over my tendency to "make things better" ...fiddle with this, change that, monkey with something else, etc. etc. For my next set of tires I will likely go back to stock 195/70/14s in a nice touring tire (Michelins, Dunlop, Yokahama), I like the "lighter" steering feel on the smaller tire, and I think it has better tracking. My previous tires were Dunlop D60/a2's in stock size. Very nice tire but being a performance all season tire, it lacks comfort of a good touring tire...I got tired of feeling every detail of the road. Depends on your preference.

(I also run four snows, stock size, in the winter, so I dont need an all season tread)

If you have sport shocks, go with the D60/A2s or similar performance tire. If you have comfort shocks, go with a nice touring tire.


Good luck...let us know what size you select and how you like it.

I recently put 205/70's (Bridgestone "wet" rated) on my 300CD with stock alloy rims. Always felt the one improvement I could make on my car's very classic look is larger tires. The original equipment size just seems too small.

I am sure the engineers know their business and the smaller size somehow works marginally better (as indicated, by how the car drives), but I can't tell the difference.

Nic