Converting a gasoline Subaru Impreza car to LPG

Hubby and I are discussing whether or not to go ahead and convert our 2002 Subaru Impreza to LPG. There are quite a few gas stations with LPG around us, and the LPG is tax free until 2018. (the car should drive ok for at least another 6-8 years or so.) Right now gas is about half the price of gasoline. We estimate it would take about 3-4 years for the savings to pay for the conversion, and then actual savings begin. I know little about LPG, however, in terms of how it affects performance.

Is there anyone out there right now driving an LPG car? Comments and experience much appreciated to help make this decision.

The conversion is not total. You will be able to run on both. Sell the Subaru and buy a hybrid. Savings will be better and faster.

The loss in power is negligible (5-10%), but the consumption will be about 20% higher due to the lower energy content.

To be honest, I don't think an LPG conversion makes much sense in your case. Too much risk for too little return. If everything goes to plan you will still need 5-6 years to outperform a regular savings account, and tying up a few thousand Euros in an older car is a good bit riskier than putting it in the bank. If your living situation changes or if anything happens to the car, you may end up losing the investment, and it doesn't take much of an accident for an insurance adjuster to write off a 7-13 year old car.

A family member who is tekkie has just converted a few weeks ago. He started a new job and commutes by car 45 minutes each way so estimated he gets payback in I think 2 years. Obviously depends greatly on your mileage. I don't think I could be arsed myself, especially with the added stress of keeping an eye out for LPG stations etc, although as stated you can always fill up with unleaded when necessary.

Or better still buy a diesel. Hybrids don't save as much as some people think.

My boyfriend converted his '97 Mercedes A140 to LPG in fall 2006. I based a project for my intro finance course (US-based IT master's program) on the expected payback period, taking into account his slightly-above average driving habits (20,000 km/yr), and figured that if he drove it 5 years/100,000 km, he'd score an 18% return on his initial 2500 EUR investment - and that was at a 1.25 EUR/liter petrol and 0.62 EUR/liter LPG!

He claims that he will break even over the next few months. I believe him, as he tracks the costs pretty carefully. He's found that his petrol mileage averages about 7 liters/100 km, and the LPG is 9 liters/100 km. However, as petrol is 1.40 EUR/liter in Bavaria and LPG is still around 0.70 EUR/liter, he still feels smug. This reduces the fuel costs to what I'd pay (with my American privileges) to drive my Volvo S40 a similar distance - but in far more awesome fashion. He acknowledges that my car is way more fun to drive, but still prefers to drive his own on long trips...

Then again, I've come to accuse him of LPG-Tourism, as he'll divert 4 or 5km to fill up once or twice per long trip. He has a smartphone, so stores PDF lists of stations for relevant Autobahns and cities for a given trip. He also knows the location of all the fuel stations in our town and Kreis, I think. Our town of 45,000 has at least three that I know of. In a pinch, he can suck it up and pay for petrol like all the other poor slobs.

The conversion did not reduce the capacity of the petrol tank, so the main loss is about 5cm cargo-area height (the LPG tank is fairly flat). Since it's an A-Klasse, no big loss. The thing was a lawn mower with extra cladding before the conversion, anyway!

One factor you may want to consider: LPG vehicles are not permitted in the Chunnel, and there might be other tunnels or ferry services they're restricted from, but that's the only one I know of. As he never plans to drive to England, he didn't consider this a great loss...

LPG is so cheap because it is essentially a waste product of gasoline refining. Should too many Germans go for the conversion, the price advantage would be severely diminished.

So, um, LPG will make your car blow up in an accident! Yeah, that's it...

So, um, LPG will make your car blow up in an accident! ... in Hollywood movie!

Thanks for all the replies, especially Texmandie!

We actually have 4 cars at the moment, though only two are plated and being used right now. My trusty little ECVT Justy finally started having transmission problems a few weeks ago, so it will be sold off for parts while the Impreza is my Justy substitute. Hubby has been bugging me for several years to get rid of my 1992 SVX, which is a Subaru coupe with a 6 cyl boxer 233 PS. He spoke with the local Subaru dealer, and the dealer is now offering to convert the Impreza in exchange for the SVX + 400 Euro. The deal is starting to sound a bit interesting though I am still a little resistant to parting with the SVX. Hubby is very enthusiastic, but I'm struggling a little not to let emotions get in the way of making a logical decision.

Here's my baby when I had the head gaskets done two years ago. That's another silver SVX on the hoist behind mine. Now the car is sitting in my father-in-law's barn (next to his antique horse-driven fire engine) while Hubby and I were discussing about replacing the battery, rear wheel bearings, getting new tires and a few other bits of work done which frankly do add up to quite a bit of money.

So we could either fix up the SVX for about the price of the conversion, or do the conversion and get rid of the SVX. Tough choice for me.

One thing that people should consider - often you are not allowed in certain underground car parks if you have LPG. I know the one under our apartment block doesn't allow it.

Yes, I've been told that LPG is heavier than air, and so it settles down to the ground rather than just dispersing. That would, I suppose, increase the danger of an explosion in the lowest level of an underground parking area. It isn't a major concern for us, though. The car would either be parked in front of our house, or in our garage, or in a barn. Hubby's work place has a large outdoor parking lot. And I usually use the short term outdoor parking lot at Stuttgart airport anyway when picking up Hubby after a business trip because it is closer to the terminal.

Frankly, I try to avoid using a German parkhaus whenever possible. To my mind they are usually so badly designed that I'm always afraid of rubbing a bumper or getting a dent. Ramp spirals have a horribly small turning radius and the allotted parking slots seem designed for VW bugs and nothing larger. I hate coming back and finding dents on my doors. Have also been in the situation a few times where I ended up having to climb in a window because people on either side parked way too close to me. I've gotten in the habit of first exploring a new unknown parkhaus using our smallest car (was the Justy) before attempting it with a larger one. And I always go to the furthest area away from the entrance to minimize the chance of that happening again, or having my doors dented. Hmm...actually, I tend to do that now with all parking lots.

So... I have until Friday to make up my mind. That's when Hubby comes back from his business trip. I'm still undecided.