I have been offered a spacesaver wheel for my wife's Suzuki. Original tyres are 185/55 R17 the space saver is 125/70/ R15 the four mounting hole spacings look OK but I am a bit concerned about the difference in rolling circumference especially if it's fitted to a front wheel. I know it's a "get you home" rather than rely on the bottle of gunge but any advice or comment out there?


 3 x FL1 2 manual + 1 auto
5 x FL2 4 manual + 1 auto
Now Discovery Sport P250 MHEV SE

185/55-17 125/70-15 Difference
Diameter inches (mm) 25.01 (635.3) 21.89 (556) -3.12 (-79.3) -12.5%
Width inches (mm) 7.28 (185) 4.92 (125) -2.36 (-60) -32.4%
Circum. inches (mm) 78.58 (1995.85) 68.77 (1746.73) -9.81 (-249.13) -12.5%
Sidewall Height inches (mm) 4.01 (101.75) 3.44 (87.5) -0.56 (-14.25) -14%
Revolutions per mile (km) 806.34 (501.04) 921.35 (572.5) 115.01 (71.46) 14.3%
Forum embed code:
Speedometer Difference
Speedo Reading Actual Speed
20 mph (32.19 km/h) 17.5 mph (28.17 km/h)
25 mph (40.23 km/h) 21.88 mph (35.21 km/h)
30 mph (48.28 km/h) 26.26 mph (42.25 km/h)
35 mph (56.33 km/h) 30.63 mph (49.3 km/h)
40 mph (64.37 km/h) 35.01 mph (56.34 km/h)
45 mph (72.42 km/h) 39.38 mph (63.38 km/h)
50 mph (80.47 km/h) 43.76 mph (70.42 km/h)
55 mph (88.51 km/h) 48.13 mph (77.47 km/h)
60 mph (96.56 km/h) 52.51 mph (84.51 km/h)
65 mph (104.61 km/h) 56.89 mph (91.55 km/h)

Can't see any issue as it is only intended as a get you home spare which is speed restricted.

Thanks for that and hopefully we won't have to test it I just went and measured the diameters with a tape measure and I got 610mm vs 560mm not scientific I know but only about 9% different. 3 x FL1 2 manual + 1 auto
5 x FL2 4 manual + 1 auto
Now Discovery Sport P250 MHEV SE

you also need to check the bore size in the middle, not just the nut placement Former Mod/Member, with the most post & Chicken George Arch nemesis

..... with her bad back, would she be able to replace it at the kerbside ?



.

I think you should really have a space saver that matches the overall diameter of the original tyre.

You can see here that yours will be very dissimilar, if you insert the figures.

https://tiresize.com/tyre-size-calculator/

Your space saver will lower your car 39.5 mm on the side as the diameter will be 12.4% less.

Personally I'd not be happy with that.

The traction control (if it has one) may not be be happy with the space saver rotating more than the other wheels.

I suppose it might also invalidate your insurance should you have an accident with space saver attached. Jules

Is the wheel a proper Suzuki part, intended for that model?
If so it will have been developed, tested and approved as suitable for the car up to a maximum speed.
The differential will deal with the difference in size / rotation speed.

However if it was me Id prefer to use it on the rear of a front wheel drive car. Landrover - turning owners into mechanics since 1948

2014 Orkney grey Freelander SD4 GS.
2004 Zambezi silver Discovery 2 Td5 (Gone)
1963 Surf blue Morris Mini Minor Super de Luxe (my little toy)

Agree, if you have a flat at the front shift a rear wheel to the front & stick the biscuit on the back. No detours, & drive very carefully straight to the garage! Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

Thanks for your comments guys I have done a bit of digging around and the general consensus seems to be that this situation is fairly common and to put it on an undriven wheel ie the back ones in this case and drive straight to a garage. I can however, forsee that all sorts of messages will come up since the wheels are rotating at different speeds.
I hate to think what a 4WD like an FL2 would do in this situation of course which is why we all have full size spares however, in the new DS world there is no spare wheel well so going off road becomes an even bigger challenge. 3 x FL1 2 manual + 1 auto
5 x FL2 4 manual + 1 auto
Now Discovery Sport P250 MHEV SE

Another option & tyre plugs, as long as it's not through a sidewall.

Click image to enlarge

dorsetfreelander wrote:

...however, in the new DS world there is no spare wheel well...

I had no idea that LR had done that! That’s completely unacceptable

A reduced size or full size spare wheel is still an option on the new DS, It fits under the loadspace floor according to the LR website.

isn’t that an option at build time only? I was told on the old DS that it costs about £1500 and requires a different exhaust system. 3 x FL1 2 manual + 1 auto
5 x FL2 4 manual + 1 auto
Now Discovery Sport P250 MHEV SE

Costs £165 for a space saver steel wheel or £560-£760 for a full size alloy spare. The wheel now appears to sit inside the car in the boot floor. No idea if it is the same as the old DS in that the spare wheel could not be added after the car was built. I would have thought that there would be less overheads in having a single floor pan and a reduced number of exhaust options so perhaps that has been taken into account when the new model was designed as the spare wheel set up seemed a bit of an afterthought on the old DS.

Not available on 7 seat version I believe. Landrover - turning owners into mechanics since 1948

2014 Orkney grey Freelander SD4 GS.
2004 Zambezi silver Discovery 2 Td5 (Gone)
1963 Surf blue Morris Mini Minor Super de Luxe (my little toy)