MK4 Golf alloys on Leon - cause any problems?

[mattupnorth]

Hi...having just bought a Leon SE TDI with the standard 5 spoke 15" alloys I fancy something bigger 16/17" alloys.

I just wondered if the Mk4 Golf GTI/GT TDI 16" alloys fit without any problems like tramlining or a huge reduction in MPG?

Someone must have tried it!?

 

[Hobbiniho]

they will fit as the leon and golf are the exact same car underneath no modification needed

 

[D3DNA]

You shouldn't have a problem with it fitting. As for tram lining and mpg, you shouldn't see any tram lining more than what you could experience with your normal wheels and mpg should be the same.

 

[mattupnorth]

Cheers guys. Would the same apply for 17" Cupra starfish alloys? I wondered if they'd effect the braking and MPG slightly being heavier?

 

[matt-drummer]

Hi...having just bought a Leon SE TDI with the standard 5 spoke 15" alloys I fancy something bigger 16/17" alloys.

I just wondered if the Mk4 Golf GTI/GT TDI 16" alloys fit without any problems like tramlining or a huge reduction in MPG?

Someone must have tried it!?

I have to ask why you would expect a reduction in mpg?

 

[D3DNA]

It's the larger wheel requires more energy to initially move it. The major factor is the actual circumference of the wheel and tyre compared to the standard. Usually the rim gets bigger and the profile of the tyre smaller so the circumference will stay relatively the same. Having an odd combo such as a 16" wheel with really low profile tyres will cause the speedo to become inaccurate though this only occurs at motorway+ speeds

 

[mattupnorth]

I figured the wheels would be a heavier with more grip? only going off an experience of putting 18" alloys on my old Passat TDI, where my MPG dropped by about 5.

 

[mattupnorth]

D3DNA - thanks for reminding me, I was going to check the rolling radius against my standard 15's.

 

[D3DNA]

I figured the wheels would be a heavier with more grip? only going off an experience of putting 18" alloys on my old Passat TDI, where my MPG dropped by about 5.

The 18's are wider and the contact patch would have increased as such.

 

[matt-drummer]

It's the larger wheel requires more energy to initially move it. The major factor is the actual circumference of the wheel and tyre compared to the standard. Usually the rim gets bigger and the profile of the tyre smaller so the circumference will stay relatively the same. Having an odd combo such as a 16" wheel with really low profile tyres will cause the speedo to become inaccurate though this only occurs at motorway+ speeds

If the wheel is bigger the tyre will be smaller (assuming the profile of the tyre is adjusted), where does the extra weight come from (more wheel but less tyre)? Maybe from an increase in width?

I honestly can't see how even a relatively large increase in the weight of the wheels and tyres would have any serious effect on the fuel consumption, jack a car up and spin the wheels (at the back on fwd of course), it takes barely any effort at all to spin the wheels, increasing the weight by a few kgs won't make any real difference, and these `heavy wheels' will have lots of inertia that will require less power to keep them turning once they are moving thus saving fuel.

The only area where the weight is really an issue is the effct that increasing the unsprung weight has on handling and performance of the suspension in general.

 

[mattupnorth]

Well a quick update chaps. Fitted some 16" BBS Montreal 2 alloys from a Mk4 Golf GTI and the handling is unaffected, but the brakes feel like they're working a fair bit harder. Barely any difference in rolling radius and the offset is ET42 compared to ET38 of the 15" originals.

They do look a lot better (although it still needs a drop), but not sure if its worth it for the reduction in brake performance.

 

[FSiLeonMike]

D3DNA - thanks for reminding me, I was going to check the rolling radius against my standard 15's.

On a Leon 1M, when running 17" rims, 225/45/17 tyres (808 revolutions to cover 1 mile) will give a rolling radius within 1% of your 15's with the standard 195/65/15 tyres. (807 revolutions to cover 1 mile)

On those 16's, 205/55/16 should be the correct tyre size i think, requiring 811 revolutions to cover a mile

 

[mattupnorth]

Cheers, the 16" alloys are 205/55/16 so again very little difference. Didn't expect it to impact on the brakes though, presume this is the fact that the wheels are slightly heavier/more rubber on the road?

 

[FSiLeonMike]

Cheers, the 16" alloys are 205/55/16 so again very little difference. Didn't expect it to impact on the brakes though, presume this is the fact that the wheels are slightly heavier/more rubber on the road?

I went from 15s to 17s, but also had the brakes done, so really didn't notice braking issues, in fact, once the new brakes were bedded in, it felt better, but then I guess it would

 

[mattupnorth]

Did you just fit new discs/pads or go for a brake upgrade? My brakes are part-worn but still have a fair bit of life left in them.

 

[FSiLeonMike]

Did you just fit new discs/pads or go for a brake upgrade? My brakes are part-worn but still have a fair bit of life left in them.

Just new discs and pads

 

[mattupnorth]

Cheers Mike - might change the fronts when I do a service in a month or 2. Did you notice any difference in MPG going to the 17" Starfish alloys?

 

[FSiLeonMike]

Cheers Mike - might change the fronts when I do a service in a month or 2. Did you notice any difference in MPG going to the 17" Starfish alloys?

Not any real difference, but then my driving style isn't condusive to good economy