Wow, thanks for all the replies.
First of all, the lpg system was retrofitted on the car, after I drove it for about 6 years and 90k km. It wouldn`t seem that much for 6 years, but the commute here is very short, with daily trips of about 10 to 30 km. The setup for the lpg system is exactly like this:
www .agrom.ro/montaje2/_30.07/hyunday%20accent/index.htm
The engine is an MPI ( not carbureted ), and the lpg system is Tomasetto complying Euro4 standards. This is funny because the car is Euro3 ratted, but I guess that there is no harm done, except for the money in my pocket. The cost of retrofitting the system was about 900$, but there are systems for carbureted cars that can be bought with only 200$.
The lpg system is very simple - the engine starts on gasoline and when the coolant temperature reaches about 30-40 degrees C, the controller automatically switches to lpg.
The initial tune-up of the system was done at the shop, with a OBD assisted computer, and it did show. The car needs a tune-up, since I`ve covered about 4000 km. Initially, the lpg mpg was very close to the gasoline mpg, but still, not the same. This is the area that I want to investigate.
I mean, maybe insulating the engine block would help - synce lpg absorbs a lot of heat when changing state from fluid to gas.
I did try several aero mods also - a partial undertray front and back. But it seems to me that the one in the back is making things worse for the mpg.
I have a vacuum gauge installed and I use it when driving.
I did a full lower grill block: the aerodynamic on highway speed was great - the car felt very stable and the handling was great, but the mpg dropped a little because the engine wouldn`t get enough air to the air box and the cooling fan would kick in very often.
I sealed the seams on the headlights, front doors and trunk lid.
Also I have some more planned.
I wanted to implement a coolant insulated heat battery - like the one in the hybrid cars. But it seems to me that it is not worth the trouble. Instead I want to use wax to store heat - just place about 1 kg of wax on top of the engine manifold and insulate it. This way, it would absorb heat and slowly release it during the cooling period.
Great forum - I love it
