GPS-based cruise control could improve fuel economy

By Stephen Edelstein May 16, 2012

Cruise control systems are already able to keep cars from crashing into each other without the driver’s help. Now, they might also be able to help big trucks achieve better fuel economy. Mercedes-Benz’s new system, called Predictive Powertrain Control, uses GPS to read the topography ahead and shift the transmission according to the conditions.

Cruise control applies a steady amount of throttle to maintain a constant speed, but if a truck encounters a hill or other terrain abnormality, the engine might have to work harder, or waste energy, if it is in the wrong gear. The need to adjust an engine’s workload based on terrain and speed is why cars and trucks have transmissions, instead of a fixed gear ratio. By robotizing its trucks transmissions, Mercedes hopes to wring every last drop of fuel efficiency out of its cruise control.

Mercedes says Predictive Powertrain Control increases fuel efficiency by three percent. In addition to being able to shift up to a more economical gear, the system’s EcoRoll function can automatically perform single and double downshifts. In addition to monitoring changes in topography, Predictive Powertrain Control’s computers will have to account for other drivers; a car could cut off a truck and force it to slow down. With so many variables, it will be interesting to see how effective the system is in the real world.

The system is currently offered on the Mercedes Actros truck. Mercedes has offered GPS-based cruise control on subsidiary Freightliner’s trucks since 2009, but those systems could only regulate speed, without shifting the transmission.

Mercedes has no plans to offer Predictive Powertrain Control on a passenger vehicle, but if it did, such a vehicle would be pretty close to autonomous. Current cruise control systems can keep a car at a set distance from another, even when the vehicle in front accelerates. If the cruise-equipped car can also shift its own transmission, all the driver will have to do is hold the steering wheel, and possibly apply the brakes. Highways aren’t known for their curves, and Mercedes has a collision mitigation system that can automatically brake a car, so the driver’s effort would be minimal.

Editors' Recommendations

Stephen Edelstein

Contributing Editor

Stephen is a freelance automotive journalist covering all things cars. He likes anything with four wheels, from classic cars…

Cars

Tesla’s fix for faulty Cybertruck pedal is simpler than you might think

Tesla Cybertruck

Less than five months after handing over the first Cybertrucks to customers, Tesla has had to recall the electric pickup to fix an issue with the accelerator.

In a notice issued on Friday, the National Highway Traffic Safety Administration (NHTSA) said that the recall impacts Cybertruck vehicles manufactured from November 13, 2023, to April 4, 2024. This suggests that all -- or almost all -- of the 3,878 Cybertrucks being recalled are those that have been manufactured to date.

Cars

Ford Mustang Mach-E 2024 vs. Mach-E 2023: What’s new in Ford’s electric Mustang?

Blue Ford Mustang Mach-E on a rooftop

The Ford Mustang Mach-E is easily one of the best EVs for the price, offering a solid range, sleek design, and pretty good tech on the inside. In recent years, it has gotten even cheaper -- thanks in large part to a price war between it and the Tesla Model 3. And, the company just took the wraps off of the latest and greatest version of the Mach-E, labeled as the 2024 model.

The 2024 Mustang Mach-E is notably different from the 2023 iteration in some meaningful ways. So much so that we decided to take a look at the two head-to-head -- to see if it was better to pay for the 2024 model or save some cash on any remaining 2023 stock.
Design
The Mustang Mach-E looks relatively unique -- in a good way. And thankfully, Ford has largely kept the overall design the same for the 2024 model, at least when it comes to the more consumer-focused models. The car retains the slatted taillights and crossover size. It also offers a large selection of colors, including the very blue Grabber Blue Metallic, as well as Rapid Red Metallic. It's a good selection of colors, and there should be an option for most buyers.

Cars

Tesla to begin production on new, more affordable models

Tesla Model 3

With competition increasing from Chinese and other automakers, Tesla boss Elon Musk revealed on Tuesday that his company is planning to begin production of new, more affordable models in “early 2025, if not late this year.” Notably, that's earlier than the previously stated date of late 2025, though whether Musk actually succeeds in meeting the earlier production time frame is another question entirely.

The news came as Tesla released its latest quarterly figures. Revenue for the electric vehicle maker came in at $21.3 billion, down from the $23.3 billion it reported for the same three-month period a year earlier and also down from the $25.2 billion reported in the previous quarter. Profit reached $1.1 billion, marking a 55% fall compared to the same period a year ago.