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MG MGB Technical - 185/75 R14

In the archives it seems most people,myself included, run 185/70 R14's.
Has anyone tried 185/75 R14's? This should give a higher gear ratio for the highway as the tires are a little taller? I know it would make the speedo off, but this is on no importants.
Any thoughts on this?
Jimmy Chew

I have not tried 185/75/14s but my GT had 175 SR14s on it when I bought it. The 185/75/14 has a diameter of 24.9250, the 175 SR14 is 25.2992 so it is a little taller than the 185/74. There were no clearance problems, just the odometer error as you mentioned. For a tire calculater see:
http://www.mgbexperience.com/misc/tirecalc.html
Regards, Clifton
Clifton Gordon

Jimmy:

Yes I'm using 185/75-R14 tires on my B and like them. The best I can determine, they seem to give me about a 10% overdrive effect. When I'm doing 60 MPH the speedo says 55 MPH. Of this error I'm not sure how much of it is the tires and how much of it is a bodged speedo.

Overall, I like the effect of the taller tires

Bryan
Bryan Prindle

Thanks for the info Bryan & Clifton.
Jimmy Chew

Hi,
I am running 185/75R 14 on my B and I checked it with my GPS would you believe and when the car was registering 80 KM (Canada) the GPS indicated 79.4 or a fraction over 79

A great way to check speed if you have one.


Cec
Cec

Actually, I just had new tires installed on my 79 (rostyles). I put on Michelen Rainforce MX4's in the BBS recommened size of 185/70R/14. What a difference it made in the feel of the steering, It felt like power steering all of a sudden. I could not feel any resistance at all while turning the steering wheel, even when turning at a crawl. I say this because the tires that were on there previously(since purchasing the car) were Goodyear Dicathilon in size 195/75R/14.
Although, I did not have any problem with clearences, I feel now they must have been too big, based on the feel of the steering before and after.
BTW, the tire shop says that the MX4's have been discontinued now, so if you are planning on them you might want to snap them up now while there are still a few around.
FWIW,
John Fraioli
John F

Interesting as I just put on some 185/75R14's and they lightened up my steering and halp alliviate engine speed on the freeway just a tiny bit too .

I like 'em but the tire store said " no more" so I bought 5 .

-Nate
Nate

Sounds like it must just be "New Tire Syndrome"
Ofcourse, I did grease the front suspension while I had the wheels off, but I do this on a regular basis anyway.
John
John F

This thread was discussed between 02/10/2002 and 09/10/2002

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.