2018 Chevy Cruze Diesel
02-20-17, 04:47 AM
#1
Lead Lap
Thread Starter
2018 Chevy Cruze Diesel
http://www.autonews.com/article/20170220/OEM06/302209945/how-chevy-coaxed-cruze-diesel-to-52-mpg
How Chevy coaxed Cruze diesel to 52 mpg
February 20, 2017 @ 12:01 am
"There is no one silver bullet," says Craig Weddle, Cruze chief engineer. "There were a lot of little things we had to do to make it all add up."
It was a significant technical feat.
Last week when the EPA confirmed the Cruze diesel's 52-mpg highway fuel economy rating through its own testing at the agency's Ann Arbor, Mich., labs, the Cruze became one of only 4 non-hybrid cars to punch through the 50 mpg highway barrier since 1990.
And after the EPA revised its fuel economy test procedures in 2008 to better reflect real-world fuel economy, only one non-hybrid car since 1990 -- the Geo Metro XFi, also sold by Chevrolet -- has retained a 50-plus mpg rating. (The EPA has revoked certification and mileage ratings for all VW diesels affected by the emissions cheating scandal).
"Fuel economy is the reason for purchase, and we were looking for a wow factor," said Dan Nicholson, GM's vice president of Global Propulsion Systems.
The Cruze's results took a total General Motors team effort that drew in aerodynamicists, electricians, powertrain engineers, lightweighting specialists, friction gurus, calibration engineers and others.
The Cruze diesel, on the way to dealers now, even has a chief energy engineer, Eric VanDommelen, whose goal was to make sure every pound-foot of torque sent to the wheels delivered maximum efficiency and that few, if any, electrons were wasted.
Much of the technology used to boost the car's fuel economy, such as the smooth underbody, low-drag brakes and active grille shutters, came straight from hybrid cars.
GM will have its challenges marketing the fuel-sipping diesel. The car is part of a big push at GM to attract Volkswagen buyers leaving the brand in the wake of the diesel emissions cheating scandal there. That won't be easy. Gasoline is cheap and consumers are deserting cars for SUVs, crossovers and trucks. Diesel engines, thanks to VW's controversy, now have image issues.
It's also not a given that VW buyers will consider switching to Chevrolet.
Nicholson said in August that GM would be going after VW's diesel faithful, who once accounted for about 20 percent of the German brand's U.S. sales. A diesel version of the Equinox crossover is also on the way, and by the end of 2018, GM will offer 10 diesel models in North America. Nicholson said last week diesel vehicles represent a growth opportunity for Chevrolet.
But none of that mattered to the engineers who tuned and tweaked and prodded the Cruze diesel until it rolled over the 50-mpg goal line.
Not the '90s
Unlike the cramped, stripped-down '90s-era cars that got 50 mpg or close to it, the Cruze diesel sedan is smooth, quiet, comfortable and fully equipped with safety features and electronic gear.
"Certainly having a number that started with 5 was enticing, but we didn't sacrifice the rest of the car to get that," Weddle says. He added there was no pressure from upper management to hit 50 mpg.
"It was really about producing a great car with fuel economy that we thought would excite our expected diesel customer base," he said.
AutoPacific analyst Dave Sullivan calls the 52-mpg highway fuel economy rating for the Cruze diesel impressive. He notes engineers struggle for every 10th of a mile fuel economy gain and that the new Cruze diesel not only beats the old model by 6 mpg, but it bests the highway rating of the 2015 Cruze Eco, a gasoline-powered model built for high fuel economy, by a full 10 mpg.
"Other cars need two powertrains to hit anything in the 50 mpg range -- I'm talking about hybrids," says Sullivan. "Now you can get hybridlike fuel economy without the stigma of being seen in an oddly styled hybrid."The biggest parts of the Cruze's 52-mpg highway rating came from three areas: weight reduction, aerodynamics and the powertrain.
To start with, the current-generation Cruze, introduced last year, weighs about 250 pounds less than the 2015 version, mostly because of increased use of lightweight high-strength steel in the body, and aluminum in the suspension components.
"We put the mass where it matters to get the stiffness in the structure, but thinned it out anywhere where it is not absolutely needed," Weddle says.
Engineers also booked a 33-pound weight reduction under the hood. The old car's 2.0-liter diesel engine had a cast-iron block and weighed 368 pounds installed. The 2018 diesel's 1.6-liter engine has an aluminum block with cast iron liners and weighs 335 pounds.
Another key piece of the Cruze's fuel economy puzzle is its manual transmission, which requires less energy from the engine to power the wheels than the available nine-speed automatic. The six-speed manual also weighs less than the automatic.
Slippery shape
Improved aerodynamics were another important part of the equation. Many of the aerodynamic tweaks GM engineers made to the car carry over from the gasoline version.
In front of each tire, for example, a black plastic deflector pushes air away from the wheels. The Cruze also has active grille shutters, which adjust to the engine's cooling needs. When the shutters are closed, the aerodynamic efficiency is improved as air is routed over, under or around the car. Headlights, taillights, door handles and exterior mirrors saw plenty of wind tunnel time.
The 2018 Cruze diesel's aerodynamic drag coefficient -- a measurement that quantifies aerodynamic efficiency -- is 0.28, down from the 0.30 of the 2015 Cruze diesel. The lower the number, the less energy it takes to push the car through the air.
VanDommelen, Cruze's chief energy engineer, said other tweaks, including using low-friction bearings in the drivetrain and wheels, tires that have lower rolling resistance than those used on the 1st generation Volt, and managing energy usage also helped attain the 52-mpg rating.
Even though GM's internal testing showed the Cruze well over 50 mpg on the highway, the champagne corks stayed in the bottles, VanDommelen said, until the EPA confirmed it.
"We had some hopes, and we're looking forward to hitting that goal. But I didn't want to really believe it until I saw it from the EPA. Once they confirmed it, we felt pretty good," he said.
Nicholson, GM's powertrain boss, said engineers weren't sure the Cruze would attain the 50-plus rating until late last year, near the end of the car's development cycle. "We were careful not to put pressure on the team," he said, "We wanted them to focus only on delivering the best car for the customer."
VW diesel owners had routinely beaten the EPA label numbers in their actual driving. And Sullivan thinks Cruze diesel drivers can get even higher than the 52 mpg highway rating.
"Most consumers have been able to beat the EPA numbers with small displacement diesels," Sullivan says. "If Cruze owners can beat the EPA number, it might make GM the new diesel leader in a market that has been leveled to nothing."
2017 Chevrolet Cruze dieselSend us a Letter
Have an opinion about this story? Click here to submit a Letter to the Editor, and we may publish it in print.To earn the EPA's rare 50-plus highway fuel economy rating for the 2018 Cruze diesel sedan, Chevrolet engineers didn't just drop a fuel-efficient engine and transmission into the Cruze and call it done.
"There is no one silver bullet," says Craig Weddle, Cruze chief engineer. "There were a lot of little things we had to do to make it all add up."
It was a significant technical feat.
Last week when the EPA confirmed the Cruze diesel's 52-mpg highway fuel economy rating through its own testing at the agency's Ann Arbor, Mich., labs, the Cruze became one of only 4 non-hybrid cars to punch through the 50 mpg highway barrier since 1990.
And after the EPA revised its fuel economy test procedures in 2008 to better reflect real-world fuel economy, only one non-hybrid car since 1990 -- the Geo Metro XFi, also sold by Chevrolet -- has retained a 50-plus mpg rating. (The EPA has revoked certification and mileage ratings for all VW diesels affected by the emissions cheating scandal).
"Fuel economy is the reason for purchase, and we were looking for a wow factor," said Dan Nicholson, GM's vice president of Global Propulsion Systems.
The Cruze's results took a total General Motors team effort that drew in aerodynamicists, electricians, powertrain engineers, lightweighting specialists, friction gurus, calibration engineers and others.
The Cruze diesel, on the way to dealers now, even has a chief energy engineer, Eric VanDommelen, whose goal was to make sure every pound-foot of torque sent to the wheels delivered maximum efficiency and that few, if any, electrons were wasted.
Much of the technology used to boost the car's fuel economy, such as the smooth underbody, low-drag brakes and active grille shutters, came straight from hybrid cars.
GM will have its challenges marketing the fuel-sipping diesel. The car is part of a big push at GM to attract Volkswagen buyers leaving the brand in the wake of the diesel emissions cheating scandal there. That won't be easy. Gasoline is cheap and consumers are deserting cars for SUVs, crossovers and trucks. Diesel engines, thanks to VW's controversy, now have image issues.
It's also not a given that VW buyers will consider switching to Chevrolet.
Nicholson said in August that GM would be going after VW's diesel faithful, who once accounted for about 20 percent of the German brand's U.S. sales. A diesel version of the Equinox crossover is also on the way, and by the end of 2018, GM will offer 10 diesel models in North America. Nicholson said last week diesel vehicles represent a growth opportunity for Chevrolet.
But none of that mattered to the engineers who tuned and tweaked and prodded the Cruze diesel until it rolled over the 50-mpg goal line.
Not the '90s
Unlike the cramped, stripped-down '90s-era cars that got 50 mpg or close to it, the Cruze diesel sedan is smooth, quiet, comfortable and fully equipped with safety features and electronic gear.
"Certainly having a number that started with 5 was enticing, but we didn't sacrifice the rest of the car to get that," Weddle says. He added there was no pressure from upper management to hit 50 mpg.
"It was really about producing a great car with fuel economy that we thought would excite our expected diesel customer base," he said.
AutoPacific analyst Dave Sullivan calls the 52-mpg highway fuel economy rating for the Cruze diesel impressive. He notes engineers struggle for every 10th of a mile fuel economy gain and that the new Cruze diesel not only beats the old model by 6 mpg, but it bests the highway rating of the 2015 Cruze Eco, a gasoline-powered model built for high fuel economy, by a full 10 mpg.
"Other cars need two powertrains to hit anything in the 50 mpg range -- I'm talking about hybrids," says Sullivan. "Now you can get hybridlike fuel economy without the stigma of being seen in an oddly styled hybrid."
The exclusive 50-mpg club
Until the Cruze earned its 52-mpg highway rating, only three non-hybrid cars had earned 50 or better since1990. 2 were later revised out of the club.Shown below (clockwise): The Geo Metro XFi, Honda Civic CRF HF and the VW Jetta Wagon
2018 Chevrolet Cruze diesel: 30 mpg city, 52 highway, 37 combined (6-speed manual)
1990-94 Geo Metro XFi (5-speed manual)
Original: 53 city, 58 highway, 55 combined
Revised: 43 city, 52 highway, 47 combined1990 Honda Civic CRX HF (5-speed manual)
Original: 49 city, 52 highway, 50 combined
Revised: 40 city, 47 highway, 43 combined2002-03 Volkswagen Jetta Wagon diesel
Original: 42 city, 50 highway, 45 combined
Revised: 35 city, 45 highway, 39 combinedNotes: The EPA revised its fuel economy rating method in 2008 and published new ratings for vehicles alongside the old ones. Also, the EPA has removed certification from VW diesels from the 2009 to the 2015 model years.Source: EPA Fuel Economy Guide
Until the Cruze earned its 52-mpg highway rating, only three non-hybrid cars had earned 50 or better since1990. 2 were later revised out of the club.Shown below (clockwise): The Geo Metro XFi, Honda Civic CRF HF and the VW Jetta Wagon
2018 Chevrolet Cruze diesel: 30 mpg city, 52 highway, 37 combined (6-speed manual)1990-94 Geo Metro XFi (5-speed manual)
Original: 53 city, 58 highway, 55 combined
Revised: 43 city, 52 highway, 47 combined1990 Honda Civic CRX HF (5-speed manual)
Original: 49 city, 52 highway, 50 combined
Revised: 40 city, 47 highway, 43 combined2002-03 Volkswagen Jetta Wagon diesel
Original: 42 city, 50 highway, 45 combined
Revised: 35 city, 45 highway, 39 combinedNotes: The EPA revised its fuel economy rating method in 2008 and published new ratings for vehicles alongside the old ones. Also, the EPA has removed certification from VW diesels from the 2009 to the 2015 model years.Source: EPA Fuel Economy Guide
To start with, the current-generation Cruze, introduced last year, weighs about 250 pounds less than the 2015 version, mostly because of increased use of lightweight high-strength steel in the body, and aluminum in the suspension components.
"We put the mass where it matters to get the stiffness in the structure, but thinned it out anywhere where it is not absolutely needed," Weddle says.
Engineers also booked a 33-pound weight reduction under the hood. The old car's 2.0-liter diesel engine had a cast-iron block and weighed 368 pounds installed. The 2018 diesel's 1.6-liter engine has an aluminum block with cast iron liners and weighs 335 pounds.
Another key piece of the Cruze's fuel economy puzzle is its manual transmission, which requires less energy from the engine to power the wheels than the available nine-speed automatic. The six-speed manual also weighs less than the automatic.
Slippery shape
Improved aerodynamics were another important part of the equation. Many of the aerodynamic tweaks GM engineers made to the car carry over from the gasoline version.
In front of each tire, for example, a black plastic deflector pushes air away from the wheels. The Cruze also has active grille shutters, which adjust to the engine's cooling needs. When the shutters are closed, the aerodynamic efficiency is improved as air is routed over, under or around the car. Headlights, taillights, door handles and exterior mirrors saw plenty of wind tunnel time.
Engine testing involved 50 cars over more than 1 million miles.
VanDommelen, Cruze's chief energy engineer, said other tweaks, including using low-friction bearings in the drivetrain and wheels, tires that have lower rolling resistance than those used on the 1st generation Volt, and managing energy usage also helped attain the 52-mpg rating.
Even though GM's internal testing showed the Cruze well over 50 mpg on the highway, the champagne corks stayed in the bottles, VanDommelen said, until the EPA confirmed it.
"We had some hopes, and we're looking forward to hitting that goal. But I didn't want to really believe it until I saw it from the EPA. Once they confirmed it, we felt pretty good," he said.
Nicholson, GM's powertrain boss, said engineers weren't sure the Cruze would attain the 50-plus rating until late last year, near the end of the car's development cycle. "We were careful not to put pressure on the team," he said, "We wanted them to focus only on delivering the best car for the customer."
VW diesel owners had routinely beaten the EPA label numbers in their actual driving. And Sullivan thinks Cruze diesel drivers can get even higher than the 52 mpg highway rating.
"Most consumers have been able to beat the EPA numbers with small displacement diesels," Sullivan says. "If Cruze owners can beat the EPA number, it might make GM the new diesel leader in a market that has been leveled to nothing."
02-20-17, 08:00 AM
#3
Lexus Fanatic
The little things sure do add up. The base price is $26,270, add in the most popular Sun, Sound and Confidence package for $3680..Of course you will want a power seat with your $30K car for $850....but I think you will want to leave out your leather seats and save $1125...It seems like a lot of money when you add in the tax and freight for a car that is essentially a $20K-$20K car.
02-20-17, 10:52 AM
#4
52 is great for those consistently logging tons of Highway miles at highway speeds, but look at city, just 30 mpg. That's no better than the Civic gas engine. Very small niche of buyers (at least within the U.S.) will be looking for a compact sedan, with manual transmission and diesel fuel.
02-20-17, 01:46 PM
#5
The little things sure do add up. The base price is $26,270, add in the most popular Sun, Sound and Confidence package for $3680..Of course you will want a power seat with your $30K car for $850....but I think you will want to leave out your leather seats and save $1125...It seems like a lot of money when you add in the tax and freight for a car that is essentially a $20K-$20K car.
The 1.4 liter gas powered car with an automatic gets an impressive IMO 30mpg city/40 highway, so I don't see a HUGE fuel economy benefit with the diesel, especially considering diesel is more expensive than regular 87 octane gas.
Then you have to factor in the cost of maintence/repairs for diesel powered cars. I know on the big diesel pickup trucks, if your dpf(basically the cat converter) goes south, it can be a $4-7,000 bill at the dealer to replace!!!
Lastly, I think VW has really tainted diesel's reputation in this country, especially with environmentalists and green types. A lot of them had polluting VW diesels thinking it was better for the environment.
02-20-17, 03:15 PM
#6
Lexus Fanatic
. Using that analogy, just because one Tesla "self-driving" car screwed up and killed the driver (and that may not have totally been the car's fault) all research on self-driving cars would stop.
02-20-17, 03:27 PM
#7
Lexus Champion
The little things sure do add up. The base price is $26,270, add in the most popular Sun, Sound and Confidence package for $3680..Of course you will want a power seat with your $30K car for $850....but I think you will want to leave out your leather seats and save $1125...It seems like a lot of money when you add in the tax and freight for a car that is essentially a $20K-$20K car.
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02-20-17, 03:36 PM
#8
Lexus Fanatic
02-20-17, 08:55 PM
#9
Lexus Fanatic
Diesels, in general, also cost more to produce than gas engines for several reasons. The 20:1 compression-ratios needed to generate enough heat and pressure to ignite air-fuel mixtures without a spark necessitate the use of a lot of very strong metal-alloys in the block and head, along with forged high-strength crankshafts and pistons. The air/fuel mixtures, on modern common-rail and DI (direct-injection) diesels require special fuel pumps, injectors, and fuel-intake hardware. Water-separators are often added to keep the diesel fuel free of moisture...though that was more of an issue on older diesels then newer ones. Dual batteries are often standard to provide the large amount of CCA (cold-cranking amps) needed to turn the engines over in cold weather. Special glow plugs are needed to help start in cold weather. The diesel's low-RPM torque requires a transmission and final-drive unit beefy enough to accept the torque. And, on most modern diesels (the small VW TDI diesels may have been an exception) urea-injection systems, with their associated tanks, pumps, and hardware, are included to help clean up the visible black soot-particles emitted out the tailpipe. Not surprisingly, all else equal, diesels are usually going to have higher list prices than comparably-sized gas engines.
02-20-17, 09:01 PM
#10
One thing I will give the Cruze the nod for is the availability of a manual transmission on all trim levels. Granted few people will order one, but its nice that if you want leather seats, RS package, all the options and a manual you can get one. Honda needs to take a lesson IMO, some higher trim levels of the Civic force you to get the CVT. Same thing with not offering the manual/v6 combo in the Accord sedan but does offer it in the Accord coupe. Come on its the same car.
02-20-17, 09:20 PM
#11
Lexus Fanatic
It's the same car.......but not the same driver. Coupe buyers are far more likely to be sport-oriented, and want to row their own gears, than sedan buyers.
02-21-17, 09:52 AM
#12
One thing I will give the Cruze the nod for is the availability of a manual transmission on all trim levels. Granted few people will order one, but its nice that if you want leather seats, RS package, all the options and a manual you can get one. Honda needs to take a lesson IMO, some higher trim levels of the Civic force you to get the CVT. Same thing with not offering the manual/v6 combo in the Accord sedan but does offer it in the Accord coupe. Come on its the same car.
02-21-17, 07:14 PM
#14
Lexus Fanatic
Last edited by mmarshall; 02-21-17 at 07:19 PM.
02-21-17, 07:58 PM
#15
Metallurgy and design on engine blocks has advanced tremendously over the years, I doubt we'll get back to the bad old days of the Vega(or more recent GM engine disaster, the Northstar V8). Plus I think GM is a much better run company post bankruptcy, poorly engineered BS doesn't fly out the door like it once did.