Converting a petrol engine to run on LPG isn’t much of a big deal and there are few cons to the system
Gavin Foster
You use it to cook your bacon and eggs on Sunday morning. You use it to keep the beers cool in your caravan fridge and you use it to attract moths when Eskom decides to do maintenance work at eight in the evening. What most of us don’t use liquified petroleum gas (LPG) for in South Africa, anyway is to run our cars. And that’s a pity.
Problem was in South Africa petrol’s always been easily available and relatively cheap in world terms, so while others looked for alternatives during and after World War II we carried on filling up with petrol as we always had.
In Italy there were more than a million cars running on LPG by 1990, and in The Netherlands about 700000. In Australia today LPG is used extensively and London’s cabbies are very partial to the stuff. It’s cheap, it’s safe and most importantly it’s environmentally much less damaging than petrol.
Thousands of factory forklifts have been converted to run on LPG over the past few decades because of the cleaner environment the exhaust fumes provide for plant workers. It’s also kinder to engines because, entering the engine as a gas, it doesn’t wash lubricant off cylinder walls or dilute the oil when an engine is cold.
Converting a petrol engine to run on LPG isn’t much of a big deal. A sturdy gas cylinder in the boot, a fill valve installed somewhere near the petrol filler cap, a couple of safety lock-off valves along the way to the engine compartment, a converter near the engine intake to change the pressurised LPG back to gas before combustion and a mixer.
A complete SABS-approved conversion costs about R5500 for a vehicle with a carburettor, or R6500 for a fuel-injected model.
“It’s important to remember that the entire system is an add-on,” says Byron Swart of Autogas, a company that specialises in LPG conversions in various centres. “Because of that your car functions exactly as before the petrol tank and all the original equipment remain, and you can still drive it on petrol as well as gas.”
A simple, dash-mounted switch allows you to choose your fuel source, and if both petrol and gas tanks are full the vehicle will have nearly double its normal fuel range.
We don’t believe there are many free lunches in the world today, so we started making some phone calls to the people selling the conversions to tell us about the downside of LPG in automotive use. We were pleasantly surprised to discover that there really are very few.
The first is that the extra tank takes away boot space, or load area in a bakkie. The tank, which has to be 3mm to 4mm thick for safety reasons, is also heavy.
Second, refuelling can be a problem. Fleet owners, with 10 or 15 vehicles operating from a depot and staying relatively near to base can install their own refuelling point through one of the distributors, such as Afrox, but for a private owner with one or two cars, that’s not likely to be a worthwhile option. Cost of an LPG regassing point? About R15000 to R20000.
For a security company, or a courier business, whose vehicles run from a local base for up to 24 hours a day, that would be money well spent.
Autogas has a few refuelling points around various cities where customers can gas up, but at the moment there are nowhere near enough to cope with large individual customer volumes.
Third, vehicles running on LPG are about 5% to 10% less efficient than petrol burners they produce slightly less power and travel a little less distance on each litre of fuel. Then again, at a saving of nearly R1,50 a litre, high-mileage fleet owners can probably live with that.
Safety is really not an issue. Cars have been run on gas for more than 50 years and international safety standards are high. LPG tanks are more solid than car petrol tanks and contain lock-off valves to shut down leaks. Our own SABS 087-6 standard takes care of that aspect in South Africa.
The reason that LPG is so much cheaper than petrol is chiefly because duties and levies are much lower. An added benefit for businesses is that VAT vendors can claim the VAT back on their fuel. Of course, this might change if the government decides that too many people are escaping the tax net by running their cars on the cheap they acted pretty quickly to stop farmers and truckers running their diesel vehicles on lowly taxed paraffin when various additives came on the market to make this a viable proposition.
Another factor that influences the difference between petrol and LPG prices, and one that worried us, is that of third party insurance. A levy of about 16c on each litre of petrol and diesel fuel sold goes to the Motor Vehicle Accident (MVA) fund. Does this mean that the estimated 500 to 1000 gas-powered vehicles on South African roads are actually running around without third party insurance? Back to the telephone we went.
“A claim for compensation from the fund relating to a vehicle powered by LPG will clearly be covered in terms of the Act,” says advocate Don Smart of Law Call, after going off to consult his papers. Of course, if enough cars switched to gas there would have to be a mechanism established to fund the MVA from automotive LPG sales.
It’s clear that the average motorist isn’t going to be switching to LPG in the immediate future the infrastructure to supply them with fuel just isn’t there yet. But for commercial use, where fleets of vehicles operate within striking range of a base, there’s every good reason to change to gas and as soon as possible. It’s good for the wallet and better for the environment. Just don’t tell the government about the wallet part.