Mechanical logical facts

1. What is the meaning of LX, VX, LXI, VXI and other symbols mentioned  on cars?

It is used for differentiating car models in maruti suzuki.
XI - Petrol car
DI - Diesel car
L - Base model
V - Full option model
Z - Added features model

Now,
LXI is a base model Petrol car.
VXI is a full option Petrol car.
ZXI is a added features Petrol car

The same goes for LDI, VDI, ZDI. The only change is that it's a diesel car.

Honda: EMT, SMT, SVMT, VMT, VXMT, SAT, VAT, SCVT, VCVT etc

in honda, E, S, SV, V, VX are the variants and AT means automatic transmission and CVT means continuous variable transmission. so if a model says VCVT that means that the variant is V and it has a CVT transmission in it.

2. Why is the stroke length twice that of the crank radius in a piston engine?

• the term Stroke is commonly used in IC Engines and Reciprocating pumps.
• in case of IC Engines Stroke is the distance between TDC and BDC whereas In case of reciprocating pumps stroke = distance between IDC and ODC
• Piston to travel a distance of 1 stroke crank shaft has to rotate half revolution .
• 1/2 stroke = 1/4 th revolution of crank shaft
• half revolution = dia of crank shaft= 2 times of crank length