LPG beim Thesis

[vlad47]

That could be one reason of your consumption. Choose the gas not according to the price but quality. Gas quality is much more different than petrol. Bad gas rises consumption more than 1,5l. It's caused by low octane number and the amount of sulfur. Bad gas also causes dirt creating in reductor. So high consumption can be also made by not so good calibration and settings. On highway I usually get 9,1l (best was 8,7l) on cruise control 130kmph and 6,7 with cruise 90kmph. In Bratislava I make about 13-14l.
www.lanciathesis.eu/public/IMAG0267.jpg
www.lanciathesis.eu/public/IMAG0268.jpg

[GWB]

Are the figures you give the real LPG consumption, or are they the readings of the trip computer?
I am asking because your figures resemble the output of my trip computer very much, but I gave the real consumption calculated on the basis of LPG refueld at the station and the distance driven inbetween.

I have also noticed that the consumption is quite a bit higher with my new winter tyres, but to make a definite statement, I would like to go back to summer tyres and see the consumption there.

Best,
GWB

[vlad47]

There are not many situations I can measure real consumption, only on long distances, because engine used to start always on petrol and switch to GPL only when water temperature reaches more than 40 degrees. Well now I changed the settings and engine starts on GPL when it's hot and turns on temperature 35 degrees. Other reason why it's never well measured is because the GPL station never fills the same maximum. As new norms were agreed the station must stop filling when some pressure is reached and always different pressure is reached. Second last time I was filling I could fill more than 5 liters more than before. Of course I'm always trying to measure each time I fill and the result differences are about 0,4l per 100km. But sometimes it's 0,4l more and sometimes less so I can consider that the computer is showing right values. A few weeks ago my consumption was higher as the main gas pipe from tank to reductor was loosed. I couldn't smell anything but there where bubbles when using oil on the connection.
But I still see the prospective for even lower consumption. Will see in a few weeks after all the upgrades are done.

[GWB]

I can also measure the consumption on short distances during the warm season, because my LPG equipment allows for a manually activated direct start on LPG, which works at temperatures above 7 °C. I do this frequently because my switching temperature is set to 60 °C, and I could not convince the LPG experts to set it to a lower point (yet). I would really like to try something around 20 to 25 °C.

The figures on LPG consumption I had given are averages from data I had collected over the last few years, so I would expect that the differences between individual fillings are smoothed out quite well.

Best,
GWB

[vlad47]

Nicely done. I can start on LPG manually too, but it's not good for engine to always go on LPG, because of the valves, but I think you know the details. After all things mentioned above are done I will be able to try some more experiments without harming the engine. I'm still not suttisfied with the consumption. But I've started so many projects on my thesis that I don't know what to do first, so it would take a bit longer. I will document everything so results could be compared.
BTW can you let me know your control unit type? Maybe I could help you with some settings as I have the diagnostics for some marks.

[starbiker]

Also, ich fahre nun meinen 2.4l Benziner schon 170TKM auf Gas (alle Tankaktionen incl. Durchschnittsverbauch im Excel Sheet...): Mehrverbrauch zur Bordcomputeranzeige ziemlich genau 25%. Damit sollte man rechnen.

Gruss....Ralf

[GWB]

I have a Lovato FAST, installed in 2006 (not to confuse with the Lovato Easy FAST). No idea about the internals of the control unit, though.

Best,
GWB

[vlad47]

Hmm, I'm sorry but now I don't have the right diagnostics for your control unit. Maybe I would find some later and let you know. As it was installed in 2006 there is for sure much more newer firmware, I advice to change it. I installed my system in jan 2011 a from this time there were about 5 new firmwares. I flashed my unit 2 times and the first time made my consumption better for about 2,5l on highway and 5l in the city. Last flash made it better I can see only in the city 1l.

[GWB]

I have the control software for it, but I am missing the right connector. I have several connectors, but cannot connect my computer to the ECU.
Whether the LPG experts have updated the firmware, I don't know. I will ask them next time I get there.

As for the fuel consumption, I was also a bit surprised in the beginning about the relatively high (ca. 25%) addition in relation to normal fuel, but both LPG experts, the ones at Lancia and my current ones, have advised me to be careful with tuning down the LPG consumption because a too lean mixture will increase the combustion temperatures and thus lead to a higher risk of damage to the engine (valves, head gaskets).

Best,
GWB

[vlad47]

Yes you are right, I'm not trying to to lean the mixture, what I want to achieve is better combustion efficiency. For example now my mixture is stronger than it should be because of the older injectors.