My MG4 Spare Wheel Solution

[geekas]

Like most recent small cars the MG4 is supplied with a gunk canister and what passes for a pump, optimistically promising to get you moving from where you stopped to a tire repair facility without resort to a flat-top tow. As many experiences related on this forum show, this is going to be a much more expensive experience than what your parents had when a wayward tech-screw found its way between road and tire - both time and money. It usually ends up costing a new tire, two if the other ones have significant wear.
So I sought to short-circuit the concept by providing my own spare and I think I have done it. Firstly the use-case for our MG4 long-range is suburban and semi-rural, within home charging distance. That is within 200km of our home in Dromana, Melbourne Australia. Most of the time it will be single-passenger. Our other vehicle is a turbo-diesel capable of towing the caravan. So the spare wheel lives in a shed in the back yard with the trolley jack, chocks, and wheel-brace in the garage. It relies on one of us getting back home, loading the tractor with the aforementioned items and running a rescue mission. If that one of us is home, the cost in time will be hours, not days, and in money, less than $100 including repair and fuel.
So what spare wheel? I got a quote for an original MG wheel and the number was $470. So I had to find an equivalent for a lot less than that. First the research. The sources of this information are the owners manual and A reference guide to wheel and tire sizes for your car
MG4 original Wheels and Tyers:
Tire size: 235/45R18
Wheel size: 8Jx18
Offset: ET51 (www.wheel-size.com had it that offset range: 49-53mm would fit)
Bolt pattern: (PCD): 5x112
Wheel Centre Bore: 57.1mm
Thread Size: M14 x 1.5
Matching the above with data from other manufacturers yielded a suite of possibilities, mostly from German manufacturers, but the one I settled on was:
VW Golf MK8/GTI/R , 2.0TSI, 92Y
Tire size: 225/40ZR18
Wheel size: 7.5Jx18
Offset: ET51
Bolt pattern: (PCD): 5x112
Now the half inch narrower might seem to rule it out but in practice the difference will not produce any safety or significant handling issues, particularly considering the prospective use envisioned.
So if I got a tiered wheel it would have to be reshod with a 45 profile to keep the diameter the same to have stability and ABS happy.
Now it just so happened such a wheel was being offered on eBay not far from where I was to visit my elderly dad for $250. I bit. And it was as described with no cracks and a very small amount of cosmetic scuffing.
Now for the tire.
Original tire manufacturer: Bridgestone Turanza T005EV
Benchmark tire price: $333 each ~$300 irrespective of manufacturer.
I took it to the local Tirepower and had a 225/40ZR18 fitted. This was a cheaper Kumho KH. $275 including removal of the old tire, the redundant VW pressure transmitter, and fitment. I opted not to fit an MG pressure transmitter. It would need to be inducted as a replacement into the MG's monitoring system, only to require re-induction when the original wheel returned after repair. Better that it throw a trouble code for a faulty sensor that can be cleared once the old wheel returned. That might even be possible through the OBD connector with a cheap OBD scanner without a dealer visit or any indication that it had ever happened. I have yet to confirm that.
Anyway the MG pressure transmitters are relatively cheap at ~$25 each so I have ordered a spare from the local dealer. (That was a month ago and it is still yet to arrive).
Pictures:

Ok so the total cost of $425 might not work out on a straight cost/benefit basis, but for me there is other values that give me peace of mind.

 

[woody1]

Like most recent small cars the MG4 is supplied with a gunk canister and what passes for a pump, optimistically promising to get you moving from where you stopped to a tire repair facility without resort to a flat-top tow. As many experiences related on this forum show, this is going to be a much more expensive experience than what your parents had when a wayward tech-screw found its way between road and tire - both time and money. It usually ends up costing a new tire, two if the other ones have significant wear.
So I sought to short-circuit the concept by providing my own spare and I think I have done it. Firstly the use-case for our MG4 long-range is suburban and semi-rural, within home charging distance. That is within 200km of our home in Dromana, Melbourne Australia. Most of the time it will be single-passenger. Our other vehicle is a turbo-diesel capable of towing the caravan. So the spare wheel lives in a shed in the back yard with the trolley jack, chocks, and wheel-brace in the garage. It relies on one of us getting back home, loading the tractor with the aforementioned items and running a rescue mission. If that one of us is home, the cost in time will be hours, not days, and in money, less than $100 including repair and fuel.
So what spare wheel? I got a quote for an original MG wheel and the number was $470. So I had to find an equivalent for a lot less than that. First the research. The sources of this information are the owners manual and A reference guide to wheel and tire sizes for your car
MG4 original Wheels and Tyers:
Tire size: 235/45R18
Wheel size: 8Jx18
Offset: ET51 (www.wheel-size.com had it that offset range: 49-53mm would fit)
Bolt pattern: (PCD): 5x112
Wheel Centre Bore: 57.1mm
Thread Size: M14 x 1.5
Matching the above with data from other manufacturers yielded a suite of possibilities, mostly from German manufacturers, but the one I settled on was:
VW Golf MK8/GTI/R , 2.0TSI, 92Y
Tire size: 225/40ZR18
Wheel size: 7.5Jx18
Offset: ET51
Bolt pattern: (PCD): 5x112
Now the half inch narrower might seem to rule it out but in practice the difference will not produce any safety or significant handling issues, particularly considering the prospective use envisioned.
So if I got a tiered wheel it would have to be reshod with a 45 profile to keep the diameter the same to have stability and ABS happy.
Now it just so happened such a wheel was being offered on eBay not far from where I was to visit my elderly dad for $250. I bit. And it was as described with no cracks and a very small amount of cosmetic scuffing.
Now for the tire.
Original tire manufacturer: Bridgestone Turanza T005EV
Benchmark tire price: $333 each ~$300 irrespective of manufacturer.
I took it to the local Tirepower and had a 225/40ZR18 fitted. This was a cheaper Kumho KH. $275 including removal of the old tire, the redundant VW pressure transmitter, and fitment. I opted not to fit an MG pressure transmitter. It would need to be inducted as a replacement into the MG's monitoring system, only to require re-induction when the original wheel returned after repair. Better that it throw a trouble code for a faulty sensor that can be cleared once the old wheel returned. That might even be possible through the ODBC connector with a cheap ODBC scanner without a dealer visit or any indication that it had ever happened. I have yet to confirm that.
Anyway the MG pressure transmitters are relatively cheap at ~$25 each so I have ordered a spare from the local dealer. (That was a month ago and it is still yet to arrive).
Pictures:
View attachment 24284
Ok so the total cost of $425 might not work out on a straight cost/benefit basis, but for me there is other values that give me peace of mind.

Very comprehensive. I live in Perth and have a mg4, 64 essence. I hated not having a spare. To be honest didnt even cross my mind when purchasing. I will not travel out of metro area without a spare tyre. We dont do much country driving anyway so not a biggie. In the end not being very technical i went with a space saver by a mob called Braumach. All up $720 from the eastern states. Friend (who also has mg4) and i took of a wheel and tried the space saver. All ok, so im happy enough with that. Bloody expensive exercise though, just for 'in case'. BTW, the scissorjack supplied started to twist when we used it, on flat garage surface. Friend put his hydraulic jack next to it for safety. Will not use that jack again. My plan anyway is to call RAC or mg roadside assist to change the tyre if I get a flat in the country. Like you in the metro area we will not carry the spare, but if my wife or I get a puncture on our own, we will get the other one to bring the spare in our other car. I may also look at perhaps getting a sturdier jack? Just more money!

 

[CrustEE]

Interesting. In my previous two diesels I bought space saver wheels and never used them. Peace of mind though, and because both cars had a well in the boot, I thought it was a no-brainer. Not sure what to do with the MG4, but I have only had it for two weeks. Out of interest how obtrusive is the low pressure warning if you were to fit a different wheel without a transmitter? Does it bleep for ever?

 

[woody1]

Interesting. In my previous two diesels I bought space saver wheels and never used them. Peace of mind though, and because both cars had a well in the boot, I thought it was a no-brainer. Not sure what to do with the MG4, but I have only had it for two weeks. Out of interest how obtrusive is the low pressure warning if you were to fit a different wheel without a transmitter? Does it bleep for ever?

Hi
not sure about that as I haven't had to use the spare for a long distance. However when trying on the space saver to make sure it was ok I took the car for a little test drive, probably less than half a kilometer and there was no aggressive beeping