Changing suspension components

I would consider it good practise to always renew suspension springs and shock absorbers in pairs, especially on sports or Quick cars.

See that a lot with the lotus specialist lots of shiny new fitted easy to test

In the case of suspension parts, yes.

Doesn’t matter which way around it is, matching parts is good working practice.

OE parts may we’ll perform better, but I don’t want my offside to perform better than my nearside, that creates imbalance. I’d rather they both perform the same.

Equally, I’d rather have two budget tyres across an axle rather than one budget and one Michelin. Of course, the preference is two Michelin

Interesting, why then would the aftermarket spring be designed to have a serious arc present to remove load from the bearings, yet VW OE springs are aligned vertical for the same make and model of car. 

Either that or it's a poor quality Ch1neese copy or something!!

My main concern with the spring though was not that it was arc shaped but the extreme end that locates in the spring seat was also distorted. This what I refer to as distortion some of us in the trade would look upon that as a defect such as badly produced for some reason. The spring industry says that some applications require custom designs. The spring industry also points out that attention should be paid to the design of the spring ends or terminations. This is where I had my reservations about the spring, it seems the angle of the termination was such that locating the spring in the lower spring seat correctly proved difficult, but even after fitment and checking the spring termination location along with the extreme end of the spring, it appeared to sit in the spring seat okay, but when assembled and aligned to the inner wing, the spring arc could be seen, provided you knew to look for it. 

When I examined the terminating ends of the spring and was unhappy with what I was looking at, I chose to believe that the spring was badly manufactured. The spring industry has this to say about springs...

Treatment of the terminating end of a spring, machining or pressing to facilitate the alignment adds cost to the production of the spring, and this also has an influence of the performance of the terminating end of the spring. If the ring of the terminating end is such that the alignment is brought into question, then the performance of the spring will be questionable.