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Matt
Matt, Mechanical Engineer
Category: BMW
Satisfied Customers: 22000
Experience:  BEng hons Mech engineering, in auto industry 22 years
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I have 2002 e46 I converted into lpg gas. What is a tune up.

Customer Question

I have 2002 e46 I converted into lpg gas. What is a tune up. I'm suffering from high fuel consumption.
Submitted: 3 years ago.
Category: BMW
Expert:  Matt replied 3 years ago.
Hello


1st question

is the fuel consumption bad when its running on petrol?

or is this no longer an option?
Customer: replied 3 years ago.
Fuel consumption on is normal but in gas is worse than pertol
Expert:  Matt replied 3 years ago.
Hello

Ok if its only worse on LPG can I ask what gas injection system are you on and does its adjust the spark timing?

as LPG fuel consumption is naturally worse than petrol due to it containing less energy, even on a well setup system you'll be about 10-15% worse on fuel consumption - but then LPG is so much cheaper its still worthwhile


Without advancing the ignition timing on gas then it'll be a lot worse than petrol
Matt and other BMW Specialists are ready to help you
Customer: replied 3 years ago.
It's only worse on gas I'm using BRC system muti point inkjectors.
Expert:  Matt replied 3 years ago.
Hello Foysal

OK the BRC system is just for the gas / fuel side of things

ther's no provision to adjust the spark advance with this system
so to improve the mpg you need to add a device like this

http://www.aeb.it/products/timing-advance-processors