yaar, kafi mazak ker liya hey.. ab jo pucha tha bhai nay ussay bata do.
look buddy i lowered my cultus, 3" down. front per thori alteration kerwani perti hey if u have to lower it bit too much. but u have to be carfull while u drop ur car, i was the only one person who used the car, so i didnt had to worry for the weight thingy and bumps. but yeah on speed breakers and bumps i had to go dead slow coz otherwise shocks and tyres ki maan ko aaho.. the ppl in USA and other countries have good suspensions like skunk2 and other companies which design the suspension for lowering.
secondly if u lower ur ride then tht means less life of ur shock absorber coz these are not designed for tht pressure.
the only way is get old springs from bilal gunj and have atleast cut 3 coils of it and ur car will be down to earth. ur breaks will be improved too by lowering and road clearance would be better too. thts what i felt after i lowered my cultus. i dont know about diesel engine so cant tell u how to improve the acceleration(Pic) of ur car.
aik kaam ker lo, take out all the seats and dashboard, remove the doors and trunk. plastiv ki chair rakh low Pic increase ho jaye gi shaid thori si.