Hi, Top Gear!
I found a 2000 Ford E-150 Chateau being sold at P650,000 with a mileage of 49,800km. I know the E-150 drinks a lot of petrol at the rate of four to five kilometers a liter. Is it wise to convert it to LPG? Is it a better choice compared with buying an over-priced 1998 Korean van priced at around P350,000?
It would depend on how you look at it. On one hand 2000 Ford E-150 will be more luxurious than a 1998 Korean van. On the other hand, you can get two Korean vans for the price of the E150 with an SGI LPG kit. Or you could also get a later model Korean van priced about the same or close to what it costs to get the 2000 E-150 and be done with it.
Assuming you were to go for the 2000 Ford E-150 and retrofit it with an SGI LPG kit, you will have to choose one capable of being tuned precisely to enable the E-150 to perform close to or even better than when it's running on petrol. There aren't too many LPG kits out there that can do this despite the claims. I don't have personal long-term experience with all of them but I would look closely and talk to vehicle owners using LPG kits before making a decision.
You will likely encounter poorer fuel economy with the LPG kit than with petrol. You'll need to crunch some numbers to see if it's worth it. Right now LPG is sold at about P23 while unleaded gasoline is priced at around P40.
If you'll be getting 15 percent less fuel economy with LPG then your 4km/l on the E-150 will become 3.4km/l. To travel the same 400kms as you would get on 100 liters of petrol you would need about 117.6 liters of LPG, or P2,704.80 against the Php 4,000 you would need for petrol. That amounts to about P895.20 in fuel savings.
That would also mean that you will need to refill your fuel tank about 100 times before the fuel cost savings will pay for itself as typical SGI LPG kits for 8-cylinder engines are at about or more than P80,000. That's the only time you can say you are truly saving on fuel costs.
You'll also have to remember that this assumes the SGI kit you get is one that works as promised.
At current fuel prices I would probably just keep the E-150 running on petrol and get it's tuning optimized on a dyno with the aid of tuning boxes (piggyback ECU's) or similar solutions (ECU reflashing, if available) and keep it in good running condition--if the E-150 is what you really want.