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Discussion Starter · #1 ·
Has anyone tried this? I would be very interested in seeing the efficiency difference. I've seen some posts saying 15 inch wheels should fit the e-Golf no problem.

I often see the chunky rubber tyres with 15 inch wheels on various taxi toyota prius near me, and i think they kinda look cool in a weird way.

The e-Golf is already a very efficient EV, so it would be cool to see what kinda numbers we can put up if the boundaries are pushed.

Wheel Car Tire Vehicle Motor vehicle
 

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You probably want to verify 15 inch wheels really fit. Also, unless you get aero 15 inch wheels, I suspect you'll lose range. Can't you put 195mm wide tires on the stock rims?
 

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You might want to run it past your insurers, they could reject a claim if you fit under size tyres and don't declare the modification.
 

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Discussion Starter · #4 ·
You might want to run it past your insurers, they could reject a claim if you fit under size tyres and don't declare the modification.
195 should fit the stock rim appropriately, cars like the bmw i3 come stock with them afaik
 

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195 should fit the stock rim appropriately, cars like the bmw i3 come stock with them afaik
205's were the narrowest tyres fitted to the e Golf by VW from the factory, if you fit narrower tyres and then have an accident the loss adjuster will almost certainly instruct your insurers to reject the claim and leave you liable for all the costs for all parties, but hey ho it's up to you.
 

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The e-Golf spins it front wheels easily with the standard larger wheels, so it’s going to be even crazier with smaller ones.
 

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What are the tyre sizes listed on the plate either on a door shut or charging flap? If 195 is not listed you’d have to check with insurers etc.

I did have an eGolf loaner a while back and never checked that sort of thing. Great car though but thought it was too expensive back then.

I have a set of 195 Nokian winters on 15 rims for our diesel Golf as it’s a listed and approved size.
Can’t say I’ve noticed any difference in economy but way to many variables to measure.
 

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I’m looking to go the other way and sell the 17s set with 225/50/17 tyres when I’ve changed to winters. Decided mainly for looks and handling to go for a staggered 18 inch setup, wonder what the hit would be on a small battery phev. Insurers fine with this as I’m fitting factory fit OEM…
 

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205's were the narrowest tyres fitted to the e Golf by VW from the factory, if you fit narrower tyres and then have an accident the loss adjuster will almost certainly instruct your insurers to reject the claim and leave you liable for all the costs for all parties, but hey ho it's up to you.
You're saying this on the basis of your legal knowledge and/or experience.

You are right that it might give then an opt out and they always look for an opt out, but it would not make the car illegal, and whether it has made any difference to the performance of the car, how? How would it have changed the performance of the car?

If you are going to argue 'grip' then a) the size of footprint makes no difference to the levels of grip of a tyre and b) the make of tyre will have a profound change in the performance of the grip so are you now saying that swapping factory tyres for another make will be struck off by the insurance company?

Just tell the insurer and they can tell you straight back if they are OK with it or not.

The answer to your question whether it'll make a difference is that wider tyres present a bigger aerodynamic section, this is why if you look at homologation of different tyres the larger tyres are always worse. Yep, hard to believe but 4 cm of reduced width really makes a difference. But driving more economically would make an even bigger difference so until you have maxed out hypermiling then try that first.

Also, VW tend to fit little aerodeflectors in front of their tyres (on the bumper trim), so in fact will probably make no difference at all and as mentioned the aero of the wheel rims then becomes your important factor.
 

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You're saying this on the basis of your legal knowledge and/or experience.

You are right that it might give then an opt out and they always look for an opt out, but it would not make the car illegal, and whether it has made any difference to the performance of the car, how? How would it have changed the performance of the car?

If you are going to argue 'grip' then a) the size of footprint makes no difference to the levels of grip of a tyre and b) the make of tyre will have a profound change in the performance of the grip so are you now saying that swapping factory tyres for another make will be struck off by the insurance company?

Just tell the insurer and they can tell you straight back if they are OK with it or not.

The answer to your question whether it'll make a difference is that wider tyres present a bigger aerodynamic section, this is why if you look at homologation of different tyres the larger tyres are always worse. Yep, hard to believe but 4 cm of reduced width really makes a difference. But driving more economically would make an even bigger difference so until you have maxed out hypermiling then try that first.

Also, VW tend to fit little aerodeflectors in front of their tyres (on the bumper trim), so in fact will probably make no difference at all and as mentioned the aero of the wheel rims then becomes your important factor.
I wouldn't completely agree with footprint not effecting grip (I understand where you are coming from with friction being the relationship between weight and the surfaces and area is not in the equation), but you are correct that tyre choice has a much greater effect. What the insurance company might have a bigger problem with is the difference in speed rating, especially if a blowout was involved.

Tyre width isn't going to make much difference, but the higher profile of the sidewall will have a greater effect on efficiency.

Will it make a difference? yes.

Will it be worth the effort over 16's? probably not.
 

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I wouldn't completely agree with footprint not effecting grip (I understand where you are coming from with friction being the relationship between weight and the surfaces and area is not in the equation)
It only affects grip if the tread temperature becomes excessive. This is why sports cars have big tyre contact areas, it reduces the operating temperature while they are subjecting it to pretty much continuous slip.

For a road car in a climate such as ours where the tread temperature is usually too low, a narrow tyre will usually exceed the performance of a wider tyre because it heats up more easily.

Of course if you are spanking the car to the max around roundabouts, the narrower tyres will start drifting out before wider tyres would, after your 3rd or 4th roundabout, tyre surfaces will heat up that quick.

The point at which narrow tyres boss wider tyres is in wet and colder conditions; they are better at both gripping through a wet weather surface film and also are more efficient as about 10% add-on losses are sustained in wet weather arising from the surface energy interactions which are a function of surface area, not load.

I would always advocate the narrowest tyre you can possibly fit. I found winter tyres in 175 profile for my Subaru some years back and it was literally unstoppable in a few inches of snow felt virtually normal. I'd use the untouched 'fast lane' on motorways covered in snow and leave the 'cleared' inside two lanes for others.

I also like smaller rim diameters which usually come with smaller widths. Why people like to be within a couple of inches of those potholes never ceases to amaze me. The more inches of rubber I can put between the road and the car's solid bits (the rims), the better.
 

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Discussion Starter · #13 ·
I’m looking to go the other way and sell the 17s set with 225/50/17 tyres when I’ve changed to winters. Decided mainly for looks and handling to go for a staggered 18 inch setup, wonder what the hit would be on a small battery phev. Insurers fine with this as I’m fitting factory fit OEM…
Staggered? On a FWD? Are your front wheels wider?
 
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