Wheel Change - Offset Query

[WhisperingWasp]

PHers, help a fella out. I'm a pretty smart guy I promise, but offsets are my kryptonite .

Thinking of getting some new wheels and chunkier tyres for our Jimny.

Options are - based on stock availability - a 15" ET-15 or 16" ET0. Preference is the 16" as will stick out less and offers better tyre choice. However, the ET0 puts the wheel 14.1mm closer to the suspension.

I'm thinking that the larger wheel diameter mitigates this somewhat, since there is more clearance from the larger diameter. Is this correct? Is 14.1mm a lot in terms of this sort of thing.

Calcs as follows:

15"


16"

[Glenn63]

If the standard wheel is <14mm away from the strut then you’ll have a problem.
Go have a look underneath at how much clearance there is, I’d suspect 14mm will be fine.

[WhisperingWasp]

Thanks Glenn. Thinking about it I might go 15 in case the wheels are st and I can then put the tyres on the standard alloys…

[350Matt]

Coming further inward with less ET than stock can get you into trouble with the tyre contact patch and 'kingpin' inclination no longer putting the centre of grip outboard of the steering axis
this means the car will be unstable and 'twitchy'

going the other way is generally safe as you move the contact patch further away from the steering axis which increases stability
it can also make the steering heavier of course

[edc]

You might also consider a spacer.

[stevieturbo]

Can you not look at the car with the current wheels and see what clearance there is ?

14mm could be quite a bit for some cars. Depends on the makeup of the suspension etc.

Although wheels with an ET0 must be pretty rare ?

I don't think I've ever come across that before.

[WhisperingWasp]

Thanks for the replies guys.

Scrap what I said earlier about the 15s. Can't mount 215 on a 5.5 rim from what I can tell.

Spacers always an option I suppose.

Will have a look at the car in the light and see what's what. There appears to be plenty of space in and around the arches but guess it can be deceiving.

The wheels are steels if that makes a difference to the unusual ET0.

[WhisperingWasp]

350Matt said:

Coming further inward with less ET than stock can get you into trouble with the tyre contact patch and 'kingpin' inclination no longer putting the centre of grip outboard of the steering axis
this means the car will be unstable and 'twitchy'

going the other way is generally safe as you move the contact patch further away from the steering axis which increases stability
it can also make the steering heavier of course

Think 15 might be safer bet as it sits pretty much exactly the same depth inwards. But sticks out a further 4cm which sounds a lot.

[stevieturbo]

from tyre sizes, sounds like some sort of off road machine ?

[WhisperingWasp]

Gen4 (latest) Jimny. So yeah, but won't be used for that really. Just an aesthetics thing being completely honest.

[Smint]

When you're checking clearances you seldom get any issues at the rear, its usually the front where problems happen.

Apply full lock both ways and check everything, you could put one front wheel only on a really high kerb to twist the suspension (live front axle?) and again go full lock both ways.

On Prados even one size up can see the tyres catching the front of the wheelarch/bumper on full lock over not particularly large undulations, epecially if deeper treaded mud terrains are used, sometimes a 2" or so lift kit is needed to make it work.