Range depends how it's driven but 250 to 280 miles should be achievable if driven sensibly. 300 if stuck in a 50limit on the motorway all the way from the m4 to Watford and beyond for instance.
It should start normally on petrol. Check no dash lights on obviously.
Then as the car warms up, before switch over and if the system is on there would normally be a flashing led on the switch to indicate the system is active and waiting the correct parameters to switch over. This depends on time delay and engine temp settings entered in the software. This could be any time between instantly, if the car is up to temp. Or a few miles before it's warm enough. Odinarily above 60c at least Or it can run a bit lumpy or stall. So you really want to test drive it cold.
...when it switches over to gas, while driving, there may be an audible click from the rear as the solenoid clicks on on the tank, and there may be a momentary slight stumble in rpm at tick over. It shouldn't, but nothing to worry about too much. Any more than that and it's likely too cold on engine temp. And needs a tweak to raise the engine temp switch over, this might be more pronounced in colder ambient temp, such as winter. Switch over at speed should be completely seemless, unless at wide open throttle where you may feel a very slight reduction in power, this is not unusual.
Anyway, once on gas it should drive normally and the led stay on constanly, this confirms you are running on gas. Any stuttering or bogging, or lag in auto gear changes might indicate a tweak is needed. It may feel down on power by 10% or so, gas is less powerful than petrol but really shouldn't be overly noticeable to the driver.
While the system is on, the LPG fuel level is indicated by one red and usually four green or LEDs on the switch if it's full. These can be a bit randomly set as to the values entered in relation to the actual fuel level so don't expect it to be perfectly incrementally accurate. They aren't very accurate anyway. Setting the trip each fill up is a much better way of checking how many miles are left in the tank.
If it runs out of gas, it should instantly switch back to petrol and a bleeper sound, so there may be a click from the rear as the solenoid clicks off. And the led should flash again warning your on petrol. You can then press the switch to turn the LPG system off, and hence the bleeping and flashing to confirm you are now on petrol.
Depending how it's set, it might switch back to petrol at high rpm. Say at 5k. This might be to gain any performance by switching back to petrol, or, it may be to hide an issue with the set up if the installer couldn't set it up correctly at wot or high rpm, which is a more likely reason on the four pot as they are a bit asthmatic anyway.
All of this should be seamless though, it shouldn't miss or lag on changes or feel lumpy or grumpy at any point. Although lag on charges can be tricky to tune out on the cheaper kits. Having said that my first LPG kit lagged a bit at high rpm, so if you find that acceptable to drive as is, dont let the lag alone put you off the purchase.
In short, you shouldn't be able to tell its changing on to gas or what it's doing, other than via the LPG switch led indicators of course. Hence they really should be visible while driving IMO.
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Topic: What to look for in an lpg car (Read 3539 times)