Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Tyre size on a +4.

It’s time to replace the tyres on my +4, and as I want to increase the ground clearance I’m thinking of having 195/65 15 tyres fitted to the 6’ x 15’ wheels instead of the original 195/60 15.
But then I’m thinking, would I get even more clearance if I fitted 185/70 15 tyres? But would these look OK on the car, or would they seem a bit on the skinny side? And then, would the speedo need re-calibrating?
I’m in a bit of a quandary, so any help, advice or suggestions would be most welcome before I take that trip down to the tyre bay.

The overall difference in tyre diameter between 195/65 and 185/70 is only 6mm, does that then imply an additional 3mm ground clearance?

I have been looking at 185/70 profile to replace the ones on my TR, but the only realistic option in that size are the Vred sprint classics (which are good tyres, but I wanted a bit of choice!)

There may be more choice in the 195 width.

The 185/70 tyre will only gain you 2.5mm in ground clearance by comparison to the 195/65 tyre. You need to be sure that the rim width is ok for the narrow tyre too. The 195/65 gains 10mm by comparison with the 195/60 profile. One possible issue is that the load rating of most 195/60 R15 tyres is 88 whereas the 195/65 R15 tyres usually have a load rating of 91.

Sid, a small point to consider is the clearance of the spare tyre under the third rear brake light if you have one.

What about a 195/70 to increase ground clearance?

?http://www.reifenchampion.de/uniroyal-rainmax-195-70-r-15-97t-rf-sommerreifen.html?adword=google/pool/reifen/productextension

On a light car like the Morgan the load rating is not an issue with either tyre.

Sid, with credit to Gambalunga, I changed the tyre profile last year, due to the low ground clearance on my 2011 Plus 4. It does make enough of a difference to be worth it.
The original tyres were 195/60/15 88H and the new tyres are 195/65/15 95H, these give approx additional 10mm clearance.

The tyre does fit into the spare wheel hole with the Cyclopes rear lamp. If you are unsure ask the tyre fitter to try the reacement tyre before you commit.
The accuracy of the speedometer readings inproved on my car when measured against GPS, and cosmetically I prefer the way the tyre fills the wheel arches.

I use 195/65/15 Dunlop Sport Bluresponse with greatest satisfaction on my 1973 911T. This era 911 is among the most critical cars re tyre performance. So I would think same tyre will also go perfectly well with your Plus 4. Load index of 91 is very ok.

I would like to add that the performance, also in the wet, is about the best.
In comparison, re 185/70/15 you have only two choices, and one of them is brutally and rediculous expensive, the other one less than average in the wet.

Oh, I did tell my insurance company about the change, Gott and Wynne were happy with the change, it certainly made no difference to my premium.

I have no regrets with the change.

If you go wider be careful about the clearance at the front between the inner sidewall and the upper cross tube. I only have about 5 mm on Bumble so I couldn't go to 195's. I believe that Blockley are now making 185/70 ' s.