The power of LPG
DO THE LPG TEST
To get an idea of the performance of your LPG system you can do one of the following tests.
The most accurate way of testing the power loss is by rolling road. Because this way of testing is not accessible for everyone, a simple way of testing the car in 3 test runs is given:
Go to a place where the road is more or less flat, a motorway is recommended.
Increase the speed to 80 km (50 mph) and put the car into 4th gear and leave it there!!
Give full throttle and measure the time needed to reach 130 km (80 mph).
Do this: on LPG (with the LPG mixer installed), on petrol with the LPG mixer installed,
on petrol with the LPG mixer removed.*
* If your car has an LPG injection system installed do not perform the last run.
Do not try to remove the injectors!!
To make the measurement more accurate do each run 2 or 3 times and calculate the average for each run.
The times give an indication of the performance of the LPG system.
The difference between the first and second run gives an indication of the power loss caused by using LPG.
An indication of the power loss caused by the LPG system is given by the difference between the second and third run.
The difference between the first and third run gives an indication of the overall loss of power.
Typical differences that can be expected between the first and last run:
1. 0% extra time or less is superb
2. 5% extra time or less is extreme good
3. 10% extra time or less is very good
4. 15% extra time or less is still good
5. 25% extra time or less is acceptable
6. 40% extra time or more is bad to very bad
We tested a RANGE ROVER 3.5 EFI automatic with an
Original on petrol: 18 sec.
On petrol with the mixer installed:18.5 sec
On LPG: 20 sec.
We also tested this car on the rolling road using a 50mm venturi mixer. The losses we measured were 0.9 % at max. toque and 4.6% at max. bhp.
Also we tested this car on the rolling road using a 40mm venturi mixer.
This time we measured a loss of 1.3 % at max. toque and 9.4% at max. bhp.
Those results can even be improved by installing an IWEMA-LPG timing advance processor.