I'm still learning about my new car - MY2006 L322 4.2SC - and have a question about the suspension. I have been looking at suppliers of replacement air suspension components and see that there are different parts for diesel and petrol cars.

Is this simply because of the fact that they are a different fitting, because of the layout in the engine bay? Or are they actually different in their operation? Are they actually softer or firmer?

I suppose the more general questions are - Do different L322 models have a different suspension feel? And can the ride quality be changed by using different shock absorbers/ air bags?

I know that the later L322s had the CVDs fitted and I believe that they give a smoother ride. But not available for my car.

I have just changed my wheels and tyres from 20's to 19's, and that little bit of extra sidewall and new tyres has made the ride more comfortable. I'm wondering if there are any more comfort gains to be had when it comes to the point when my suspension needs changing.

Cheers

You would be better off putting 255/55/20 tyres on your original wheels... That vastly improves the ride quality sir...

Thanks. I've put 255/55/19s on - Pirelli Scorpion AT plus. I've only put 1000km on but so far I am impressed.

The older non CVD system was as soft and as comfortable as it got for the L322. AFAIK the spring rate of the air bags are the same across all vehicles and the dampers are as well unless someone has fitted 'uprated ' ones. All terrain tyres generally have a stiffer sidewall so this may contribute to some increased ride harshness. 2012 TDV8 Vogue (L322)

Don't be tempted to fit rear shocks from a 3.6 as they are longer than for other engines to go with the longer air-springs.

Air-springs can mask worn-out shocks compared with steel springs and worn-out shocks don't absorb bumps well, making the ride harsher.

JayGee. Thanks for that. I thought that I read somewhere that the supercharged L322s had a sportier/firmer ride than other models, but after searching around, I have not found any confirmation of that. Maybe I just misread something.

I take your point about AT tyres having stronger/stiffer sidewalls. These AT Plus have a Load Index of 111 and so far seem to be pretty comfortable. Better than the same size Hankook road tyres they replaced.

Graeme. Interesting point about air springs masking worn shocks. I don't think I've got any issues, but I have no idea on the age of the parts. I know the front shocks/bags were changed in 2018. But can't see dates on rear parts.

I have read many of your posts regarding your tyres, and your particular usage of them. Your comments were very useful in helping me decide to go with the Pirellis. Thanks. I too would have preferred 60 profiles, but they are even harder to find here in NZ than in Australia.

I temporarily fitted RF10 in 255/55R19 from my D4 when I first got my L322 which I found quite harsh.
Having used AT+ I think you've made a good choice. They were planned to be made in 255/60R19 which would have been my preferred option having used them in 275/55R20 but they didn't eventuate.