Solving the multi-fuel dilemma
The facility for a petrol engine to run on a multitude of fuels using just one fuel tank is the next holy grail to have been achieved by automotive engine designers. However, this has not happened, as you might expect, from recognised automotive manufacturers in Europe, Japan or the USA, writes Anthony Lewis.
The breakthrough has come from a small team of Brazilian engineers near São Paulo who have produced a 'smart' logical thinking engine management system that could make life easier for millions of motorists not just in South and North America, but across the globe.
As a result of their pioneering work, Brazilian motorists who buy cars equipped with Delphi's multi-fuel technology, which came on to the market in July, can pull onto the forecourt of their nearest filling station and fill up their vehicle with whatever is the cheapest fuel that day - without having to worry about whether their car will perform properly.
The system has been initially launched using 1.8 litre GM engines. The engines exhaust system oxygen sensor detects from the engine emissions whether you have filled up with regular petrol or alcohol fuel, or have a mixture of both in the tank. The sensor feeds this information back to the engine management control unit and that in turn adjusts the electronic mapping to make sure the engine is working at its optimum best whatever fuel is being used. The mapping system can control the volume of fuel needed, the air/fuel ratio mix and on engines with variable injection timing, the number and length of injections needed per cylinder, per cycle.
It's not just the software for the mapping system that has to be altered - fuel pump, gaskets and piston rings all have to be modified to counteract the corrosive effects of alcohol.
In Europe there is a relatively simple choice of fuel, petrol, diesel and LPG with other minority options just coming to market, petrol/electric hybrids for instance.
LPG needs a separate fuel tank, a saving in fuel costs and emissions but a gain in vehicle weight and a loss in load carrying capacity if it is fitted in the boot or the loss of a spare wheel if it is fitted in the spare wheel carrier area under the floor.
In emerging markets, issues are not so clear cut and alternative fuels formulated from plentiful locally grown sources of energy are pioneering a revolution in combustible fuels.
The USA's National Ethanol Vehicle Coalition recently launched a six-state initiative to promote greater use of E85, the ethanol/petrol mix, as an alternative to petrol just as engineers working at Delphi Corp's technical centre in Piracicaba, near São Paulo, launched its multi-fuel engine management system.
The NEVC estimates that the market for E85 has increased ten-fold during the past five years, to about ten million gallons a year. It has launched its new promotion in Wisconsin, Missouri, Colorado, Minnesota, Michigan and Illinois.
E85, which is 85 per cent ethanol and 15 per cent petrol, is currently made from domestically-produced corn. Price and performance is similar to that of regular petrol.
The big advantage of ethanol is that it is renewable, it produces fewer emissions and helps reduce demand for imported oil - by 98,000 barrels a day which in turn reduces the US trade deficit by $1.1 bn a year.
There are an estimated three million flexible fuel vehicles in the US, able to run on E85 or petrol.
In Brazil, most cars run on E100, which is 100 per cent alcohol, or ethanol, fuel, produced from sugar cane.
Knowing that both Robert Bosch and Magneti Marelli were working on similar systems, Delphi's research and development team pulled out all the stops to deliver their system in just eight months, said Roberto Stein, chief engineer at the Centro Tecnologico.
It means that from now on, motorists won't have to decide whether to buy a car that will run only on ethanol or only on petrol.
Although this is a particular dilemma for Brazil, the breakthrough engine management system (EMS) has implications across the globe, anywhere motorists have a choice of ethanol, methanol or petroleum-based fuel.
"China, for example, India and Africa could all benefit from this technology," said Stein.
The Brazilian government encouraged the country's auto industry to switch to ethanol-based fuels in the 1980s, when oil prices were high and sugar cane, used to produce the alcohol fuel, was cheap and plentiful.
This led to 90 per cent of Brazilian cars running on E100, the 100 per cent ethanol fuel. But as fuel prices dropped in the mid-90s and sugar prices rose, the market started to switch back to petrol-powered engines, said Stein.
Bosch started working on a multi-fuel system in the early 1990s and Delphi gained some background knowledge with its work on the US E85 fuel, said Stein.
One of the major problems with alcohol is that it is more corrosive. It also works best with engines using a lower compression ratio, typically 9.5:1 against the typical 12.0:1 found in petrol engines.
The compromise for the multi-fuel engine is a compression ratio of 10.5:1 - "a halfway house," as Stein describes it. He is particularly excited about the multi-fuel potential of GM's 1.0 litre engine which could operate on a 12:1 compression ratio for both alcohol and petrol. "Using an engine of this capacity I think it would be very good for overall fuel consumption and performance," he said.
Work on the multi-fuel project began in August 2002 and by October, Delphi had a fleet of 10 cars running in normal, everyday use while durability tests were conducted at GM's São Paulo proving ground.
One extra advantage of the multi-fuel EMS is that it also detects the difference between summer and winter and makes minute adjustments to maintain optimum performance and emissions.
The Piracaciba technical centre, about 120 miles north-west of São Paulo, along, appropriately, the Sugar Highway, works on "filler tank to exhaust pipe" technology - not just the engine management systems but fuel systems, injection systems and exhaust emissions.
The technology from there is exported to countries worldwide including Saudi Arabia, Mexico, Egypt and South Africa where many of the driving conditions are similar to Brazil, including temperatures and emissions legislation.
The centre opened in January 1999. From just 10 engineers then, it now employs 70 and has a total staff of 110.
|After Volkswagen launched the first Brazilian-made vehicle with a flex-fuel system engine, the Gol Total Flex, General Motors do Brasil has responded with a rival model, the Chevrolet Corsa Flexpower in hatchback and Brazilian-designed sedan versions, writes Rogério Louro.
In conjunction with Delphi, GM do Brasil developed a flex-fuel system that allows the 'Powertrain' 1.8-litre eight-valve engine to run on petrol, alcohol or a blend of the two. Power output varies between 105hp and 109hp depending on the fuel used.
Following the launch of the 1.8-litre flex-fuel engine, GM Brazil is stopping production of its 1.8-litre petrol Corsa. In contrast Volkswagen is still selling its 1.6-litre petrol Gol following the launch of the 1.6-litre flex-fuel version.
GM expects that adding the Flexpower version will increase sales of 1.8-litre Corsas from 800 units per month to about 1,000.
At the end of the year, GM will also launch a 1.8-litre flex-fuel version of its new Chevrolet Meriva, the GM Europe-designed 'mini minivan' first launched in South America and now being rolled out in other markets with Opel and Vauxhall badges.
GM do Brasil now plans to sell flex-fuel versions of all its range, including the (also GME-designed) Astra, Vectra and Zafira. Fiat and Ford, too, are preparing to launch flex-fuel vehicles in Brazil. Fiat will introduce flex-fuel versions of the Palio and Siena while Ford is developing a version of its Ford of Europe-designed Fiesta model.
Volkswagen will also extend flex-fuel engine availability to the Parati station wagon and the Gol-based Saveiro compact pick-up.