Hi all
I’m looking for advice on Wheel Size i have a mk 1 which has 185 55R15 wheels on at the moment. these alloys are very scabby so the plan is to have then blasted and powder coated or buy new or second hand alloy also due for new tyres.use the car for fun I like a spirited drive now and again so the question is what is the advantages of 15" wheels over 14" wheels (I know 15" makes speedo inaccurate but can cope with that ) regards weenie
Hi, the MkI guys will tell you the best 15" size to go for but going to 15" lets you use a lower profile tyre for the same circumference which gives less flex and better handling.
Aspect ratios have been dropping for years, for a long time in the 70’s and 80’s after radials became standard 70% was “low profile”, then 60, now 55 is cooking and sports starts at 50 and less.
Mk1 14" uses 185 60 14 I think which are 22.74" diam. Your 185 55 15 are 23.01" diam. That would only make a difference of just over 1% slower so the speedo should be fine as most read a little fast as standard but you can check it with a sat nav how it runs at the moment before deciding. 195 50 15 would be almost exactly the same diam as the standard 14", lower profile, and a tad wider if they clear ok but I’m sure others will know more.
Here’s a good calulator to see the difference the width, aspect ratio and wheel diam have on overall diameter/circumference, http://www.csgnetwork.com/tiresizescalc.html
195/50/ R15 will be a little wider than 185/60 R14 so will give more grip, the smaller aspect ratio will mean less tire wall flex during high speed cornering and a slightly less comfortable ride. The 14’s being slightly narrower will more more entertaining at lower speeds. You will have a greater choice of tires if you go with 15s and 15" wheels are asethically more pleasing to most.
If you want it to be ‘fun’ to drive I would go with 14 for a standard car.
I have 16s with 205/45s on there. Must be very similar circumference as standard, as my speedo seems pretty accurate according to those flashing ‘your speed’ nanny state boards.
Biggest problem is the hike in price - best part of £100 each for good tyres at that size.
I have both. My car as standard has 195 50 15 on 15" rims.
I got a set of 14" rims while my original wheels were being powder coated. If your manual states you need V rated tyres there are not a lot in the 14" size but lots in the 15" size and less expensive at 15"
On a club run where you are realy pushing it you can feel the back end step out of line a little with the 14" wheels, with the 15" wheels it stays planted, not a big problem just a higher level of roadholding and the 14" wheels and tyres just move a little.
With regards to comfort, the 15" tyres are inho and my good ladies opinion harsher and you have to get your seat seat correctly set for the ride to be reasonable. The 14" rims were just a lot better on the comfort stakes.
If I was replacing my wheels and tyres, I would be more than tempted to go the 14" route.
eddie
The big trouble with 14" is the choice of tyres
15" offer a much better tyre at a cheaper price
thanks guys for such a quick replys seems on cost stick with the 15" and may be some cheap 14"might come my way its on a trailer now behind the motor home for a week in the peaks weenie
A guy at Compomotive once told me when I asked about wheel sizes for my other silly hatch that light weight cars need some side wall compliance to allow the car to move around & grip the road rather than skipping about everywhere, that’s why lightweight single seaters don’t have laccy band tyres. 
Yes a good point that makes sense on real roads rather that smooth tracks anyway. Unsprung weight to body ratio, a flexible tyre can follow the road better than trying to get the whole of the wheel, tyre and suspension to. We noticed a good improvement in comfort and less crashing going from 88W to 84W on our car. Worth getting the right load rating as many tyres are made for heavier cars than our light roadsters.
15" is really the way to go, there is a lot more tyre choice and as stated above your speedo will still read true, 14" gives slightly softer ride at the expense of ultimate grip and cornering ability.