I know that I am repeating myself. but bear in mind that by lowering the car you are altering the suspension geometry, usually to its detriment. Excessive lowering will result in increased tyre wear due to the change in wheel camber. Remember to get the tracking checked as, unless your car has zero bump steer (unlikely), the toe in/out will probably have changed.
I'm pleased that you've clarified this for me. Car makers invest exorbitant amounts of money to ensure that the whole suspension/load/steering geometry will work effectively.
Without a doubt, it is possible to alter the overall ride height of any car, but doing so involves far more than simply fitting shorter coil springs and stiffer dampers.
This can often have the effect of reducing the contact patch that the tyres have with the road surface. Notwithstanding the static geometry, stiffer springs and dampers can cause the contact patch to change in shape. Overly stiff suspension can also reduce the amount of time that the tyres are in contact with the road surface.
Tyres that are not in contact with the road surface are doing nothing useful whatsoever.
Changing wheel rims and fitting tyres that maintain the same ride height can be beneficial; in some cases it allows more rubber in contact with the road more of the time. But you must make sure that the suspension can cope with the reduced compliance that a lower profile tyre offers.
I'm not saying that you shouldn't do it - I'm simply saying that if you're going to spend money to improve the quality of driving experience you might as well go all the way and make sure that you get a positive result from your investment.
It's possible to take a basic car and improve it's driveability and safety simply by having the worn and torn rubber bushes replaced; fit a set of quality tyres; check them weekly for any damage. After a couple of weeks (few hundred or so miles) get the car onto a full four wheel alignment system and have the geometry corrected. Start at the back if it's adjustable, and then get the fronts aligned to the thrust line.
There is no point in lifting a car and just aligning the front wheels to an arbitrarily line drawn straight along the f-r axis of the car.
That doesn't work. The steering will be uneven at best, off centre or even close to undriveable.
Suspension, alignment and geometry is far more complex than your average tuner thinks it is.
