Will it make any difference changing 15" Alloys to 16" Alloys on an MGF?

Question

I am looking at Changing the Alloys on my MGF, The ones I like are 16" but my current ones are 15". would it be a straight swap or would i have to make changes?

Answer 1

You'd need new tyres as well as alloys, of course. This is a popular reason to change alloys; you can usually get better performance tyres in 16" sizes because all the modern hot-hatch and rice-rocket cars use 16" or larger alloys. (For those of us with older sports cars who compete in vintage motorsport of some kind, this is even more apparent; I have a pair of old Seventies-vintage Alfas with 14" rims, and I can't find much apart from snow tyres for them these days...)

What size to buy? The MG F 1.8iVVT came from Abingdon with tyres in size 215/40ZR-16 front and rear (as opposed to the 185/55VR-15 front and 205/50VR-15 rear tyres fitted to the other cars in the MG F range). It's safe to assume those will fit and won't affect your speedometer reading.

Apart from that, the three things you need to consider are:

Bolt pattern. Make sure the wheels you're buying have the same number and spacing of holes as the wheels you're taking off. Your MG F uses wheels with four bolts on a circle that is 95.25mm, or 3 3/4" -- unique to M.G./Rover products. (Don't be fooled by wheels for Triumph Spitfires and other older cars -- the offset is wrong; see below.)

Weight. On a light car like the MGF, the weight of the wheel/tyre combination makes a big difference in how the car rides and handles. Basically, imagine a seesaw with a large weight (the car) at one end and a small weight (the tyre and wheel) at the other. Every time you go over a bump, there's an impact on the small weight. But if you increase the amount of the small weight, that same impact makes the large weight on the other end of the seesaw move farther.

Offset. This is a measure that affects how far the wheel sticks out from the piece of the car that it bolts onto (there's more to it than that, but this will help you visualise what's going on). Changing the offset of the wheel can cause problems in many areas, with the most obvious one being the possibility that the wheel or tyre will rub on the car -- either the bodywork or the suspension. It can also make the car's steering feel wonky, stiff or super-twitchy, and can ruin the enjoyment of an otherwise fun car like the MG F. The MG F uses wheels with an offset between 30mm and 35mm, so that's the range you'll want to use for the alloys you buy.

In any event, you should be able to enjoy better looks, increased performance, and better ride, steering and handling if you get the properly sized wheels and tyres for your MG F. The best indication for this is simply that Abingdon put 16" rims on the 1.8iVVT, their higher-performing version, so you know that at least one set of wheels will fit.

Safety Fast!

Answer 2

Might need a lower profile tyre depending on wheel arch clearance, and don't forget to estimate for the suspension compression.

Answer 3

Yes there will be changes - not the least of which will be n error in the Speedometer reading.

Answer 4

LOL hmmm alloy- mixture of metals right? idk