Multi-fuel Dilemma Solved with a Sniff
A new engine management system from Delphi could make ethanol a major world player.
A breakthrough in engine management systems by a small team of Brazilian engineers could make life easier for millions of motorists not just in South and North America but across the globe.
As the U.S.’s National Ethanol Vehicle Coalition (NEVC) launched a six-state initiative to promote greater use of E85, the ethanol/gasoline mix, as an alternative to gasoline, engineers working at Delphi Corp.’s technical center in Piracicaba, near S?o Paulo, launched the company’s multi-fuel engine management system.
The NEVC estimates that the market for E85 has increased ten-fold during the past five years, to about 10 million gallons a year. It has launched its new promotion in Wisconsin, Missouri, Colorado, Minnesota, Michigan and Illinois.
E85, which is 85 percent ethanol and 15 percent gasoline, is currently made from domestically-produced corn. Price and performance is similar to that of regular gasoline. But ethanol is renewable, produces fewer emissions and helps reduce demand for imported oil by 98,000 barrels a day, which reduces the U.S. trade deficit by $1.1 billion a year. There are an estimated three million flexible fuel vehicles in the U.S., able to run on E85 or gasoline.
In Brazil, most cars run on E100, which is 100 percent alcohol, or ethanol fuel, produced from sugar cane. Now, Brazilian motorists who buy cars equipped with Delphi’s multi-fuel technology, launched in July, will be able to pull onto the forecourt of their nearest filling station and fill up with whatever is the cheapest fuel that day — without having to worry about their car’s performance.
The system, being launched initially on 1.8L GM engines, detects whether you have filled up with regular gasoline or alcohol fuel, or have a mixture of both in the tank and adjusts the engine management mapping to make sure the engine is working at its best.
Knowing that both Robert Bosch and Magneti Marelli were working on similar systems, Delphi’s team pulled out all the stops to deliver their system in just eight months, says 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 — or anywhere motorists have a choice of ethanol, methanol or petroleum-based fuel.
“China, for example, India and Africa could all benefit from this technology,” says Stein.
The Brazilian government encouraged the country’s auto industry to switch to ethanolbased 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 percent of Brazilian cars running on E100. But as fuel prices dropped in the mid-90s and sugar prices rose, the market started to switch back to petrol-powered engines, says Stein.
Bosch started working on a multi-fuel system in the early 1990s and Delphi gained some background knowledge with its work on the U.S. E85 fuel, says Stein. One of the major problems with alcohol is that it is more corrosive. It also works best with engines using a higher compression ratio, typically 12:1 against the typical 9.5:1 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 1.0L engine which could operate on a 12:1 compression ratio for both alcohol and petrol. “I think it would be very good,” he says.
The system works by “sniffing” the amount of oxygen in the exhaust and calculating which fuel or fuel mix is being used. If there’s too much oxygen in the pipe, more fuel is injected. It’s not just the software for the EMS that has to be altered — fuel pump, gaskets and piston rings all have to be modified to counteract the corrosive effects of alcohol.
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 S?o 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 center, about 120 miles north-west of S?o Paulo, along, appropriately, the Sugar Highway, works on “filler tank to exhaust pipe” technology — engine management systems, fuel and 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 center opened in January 1999, formed from an engineering group within GM do Brasil. From just 10 engineers then, it now employs 70 and has a total staff of 110. This article was provided exclusively to Automotive Industries by Interchange, a U.K.-based automotive business agency and consultancy servicing media and corporate clients. Anthony Lewis is a partner in Interchange and can be contacted via e-mail at firstname.lastname@example.org