I've recently had my '89 240 converted to LPG, and thought i'd help out anyone else considering it with some pros and cons
I got my conversion at AG autogas, in lilydale, Australia. Both the converter and my mechanic (who is really more of an adviser, as i do my own work most of the time) recommended i skip duel fuel and go straight LPG, apparently it is not practical to run a B23E engine on duel. So i had to trust them on that one. Its probably the most simple conversion on the market, just feeding gas slightly downstream of the AMM
Range; Big con The tank fits between the rear wheels in the boot, and fills it up quite well, although the majority of the space is still available. The tank is 50 usable liters, whereas the old petrol one was 60, which is a bit of an inconvenience. I was getting about 6.5km/l economy on petrol, giving me a 390km range, with an extra 10L in the jerry can i would bring with me for emergencies. Now, fuel use has risen quite a bit, which is to be expected when running on gas. At the moment, in the same conditions as before i'm getting 5km/L, which brings the range of the vehicle down to about 250km. Because of the nature of LPG i have no way of adding more fuel on the go, and running out would mean i have to tow the car, so in practice this shortens the range to about 225km to ensure i never run out of fuel. This short range makes the car very impractical for driving interstate, and means i fill up twice a week instead of once :-(
Performance; con Once he is warm, the 240 goes just the same as when it was fueled by petrol, i can't tell the difference. The only time it actually makes a difference is when the engine is quite cold i.e winter morning. It always starts first time, which is actually an improvement over the old system, but it lacks power for about two or three blocks while it gets warm (ie where i used to push the pedal about 1/4 to take off, now i push to about 1/2). Not a huge drawback, but still something to consider. I'd imagine if i had a heavy trailer the car would barely move
Cost: Big pro Now this is probably the biggest factor for most people, being the underlying reason conversions are done in the first place :-). Before:
6.5km/l @ $1.20 average per liter = about 18c per km. After: 5km/l @ $0.45 average cost of LPG = about 9c per km The conversion is halving the cost of fuel each week for me, saving me about $30 per week I was charged $2500 for the actual conversion, of which the government offers a $2000 rebate down under. Total cost out of my pocked is $500, which at this rate should be paid off in about 5 monthsThats about all that i can say at this stage, i havn't had the system long enough to comment on any difference in maintenance. To put it simply, it seems the savings in fuel make it well worth the while, but that is only true if you can live with some of the disadvantages. Say, for example, you had to hire a car twice a year because of the short range, you would probably end up losing any money you saved from the conversion
However, nothing puts a bigger smile on my face than completely filling the tank for $20
Hopefully someone will find this post useful :P