E70 wheel alignment

[JBF]

So then the question is what pressure to have put in them before the alignment... I’d imagine change in pressure might change the alignment to some extent?

[ard]

Originally Posted by JBF

I’d imagine change in pressure might change the alignment to some extent?

no it wont.


alignment is a suspension/wheel thing, not a rubber tire thing.

[JBF]

Interesting. I figured changing the tyre pressure will change the way that the tyre sits on the road and therefore the angle that the wheel sits at. I guess we are talking about tiny angles and massive forces (gravity + mass of car).

Oh and an American to English translator wasn't required, that made perfect sense..

[ard]

Originally Posted by JBF

Interesting. I figured changing the tyre pressure will change the way that the tyre sits on the road and therefore the angle that the wheel sits at. I guess we are talking about tiny angles and massive forces (gravity + mass of car).

Oh and an American to English translator wasn't required, that made perfect sense..

Most modern alignmnets are done with a machine that clamps a 'fiducial' onto the wheel itself. A three legged assembly with a angled reflector. This essentially translates the angle OF THE METAL WHEEL ITSELF to the machine. The tires simply hold the car up in the air, they don't 'constrain' nor hold the wheel at some odd position. You will see them roll the car back and forth, as it sits on a roller plate- this lets the car 'find a neutral position'.

Obviously you want all 4 tires the same size, and approximately at normal pressures. (Not two at 40 and two at 20). But a few PSI, or even an alignment on old tires should not have a big impact. IMO

[JBF]

All done. The guys were really good and took their time to get it as close to what I requested as possible, let me hang around and watch, see where the adjustment points are etc. The previous state had significantly more front toe than spec and the rear was towards the upper end of the range.


In terms of feel, I can feel a difference for sure. I'm not sure how much is due to the alignment and how much is down to new rubber.

+ Steering feels lighter and more responsive - especially at low speed.
+ Does not seem to 'tramline' so much (follow the grooves worn in to the road by trucks etc).
- Feels less 'planted' or 'locked-in' when cruising down the motorway, I guess expected with significantly less toe-in than before.

Turn-in/cornering also feels a bit different; I'm not sure whether it's better or worse. Some might say it feels more responsive and turns in more quickly, some might say it feels less stable.

This is a very loose analysis after driving home 50 miles (30-40 miles motorway). I imagine it will take me a little while to adapt and for the tyres to bed in a bit.

Overall happy, now time will tell in terms of wear on the front outside edges. Only covering 5-6k miles per year it might take a while.

I'm running at 34 PSI all round; previously ran 32 all round. I'll have a play with different pressures over time.

For the benefit of anyone else looking for a good garage in South East London in the future I used 'Wheel Power' in Brockley/Lewisham.