2013 to Today, Engines under 3 Liters and Turbocharged have gone backwards on MPG and Emissions in Real World Driving

[G. David Felt]

2013 to Today, Engines under 3 Liters and Turbocharged have gone backwards on MPG and Emissions in Real World Driving

Technology today is proving to be more effective in controlled testing than in real world driving. A U.K. based company that does emission testing has been in the US running a long term testing of over 500 auto's testing real world versus testing for MPG, greenhouse gas creation and overall improvements and the end result is that with all the new technologies from Turbocharging, start-stop, lightweight materials and eco-drive settings that the top 4 things have shown up to Quote the story:

• Vehicles with engines smaller than 2 liters have essentially posted no change in fuel economy. Meanwhile, the fuel economy of engines between 2 and 3 liters, the most common, dropped by 8 percent, and fuel economy rose by 8 percent in engines of 3 liters or larger. The drop in economy for the most common engine class is problematic for overall CO² emissions in an era of cheap gasoline, when Americans are commuting longer distances but small-car sales are lagging.
• While the EPA's five-cycle test procedure tracks pretty closely with EA's real-world tests, automakers may be relying too heavily on "off cycle" credits given by the EPA for technologies like engine stop-start systems and "eco" driving modes that cut fuel consumption. Those systems aren't accounted for in the driving tests. That said, it's only logical that a car sitting at idle gets zero miles per gallon, while one that's turned off by a stop-start system is by definition economical.
• Turbocharged engines show large gaps between lab and real-world use, delivering big fuel savings when under low stress but becoming far less efficient once the turbos are engaged. In other words, these systems are driven with a light during testing, but real-world drivers engage the turbocharger far more often.
• Regular hybrids, which have gotten lost in the hype over plug-in hybrids and pure EVs, are among the best technologies in delivering fuel economy and cutting greenhouse gases.

What I found interesting is a very true point stated at the end, how economically we drive is negated as the technology cannot make up for a lead foot.  So having a NON Turbo V6 or V8 is better than a smaller Turbo engine it would seem!

autoblog story

[G. David Felt]

@Drew Dowdell This I find very interesting and tends to prove your own statements about Turbo small engines versus naturally aspirated bigger engines.

[cp-the-nerd]

I'm curious how this study takes into account whether a turbocharged engine is more or less efficient than the larger displacement naturally aspirated engine they replace. I generally agree that turbocharging is overrated for economy sake, and specifically when comparing real world driving to gaming the EPA tests, but there's a lack of specific information provided in Autoblog's summary of the research.

Are we being told that new 350-400 horsepower 3.0T engines are less efficient than recently defunct 250 hp N/A 3.0L engines? Are we comparing Ford's soon-to-be-retired 2.0L N/A (160 hp) to the Ecoboost 2.0T (240+ hp)? Well obviously the turbocharged version will fall flat.

I can submit a comparison of my own. My wife's former Cobalt Sport 2.4L VVT made roughly 170 hp/160 tq mated to a 4-speed automatic. This is quite comparable to her new Cruze Premier Hatchback 1.4T/6A, which makes 153 hp/177 lb-ft and offers similar straight line performance. Both are driven on the same 30 mile commute as well as day to day errands and are just a bit under 3,000 lbs. The Cruze is 8-10 mpg more efficient.

[G. David Felt]

10 minutes ago, cp-the-nerd said:

I'm curious how this study takes into account whether a turbocharged engine is more or less efficient than the larger displacement naturally aspirated engine they replace. I generally agree that turbocharging is overrated for economy sake, and specifically when comparing real world driving to gaming the EPA tests, but there's a lack of specific information provided in Autoblog's summary of the research.

Are we being told that new 350-400 horsepower 3.0T engines are less efficient than recently defunct 250 hp N/A 3.0L engines? Are we comparing Ford's soon-to-be-retired 2.0L N/A (160 hp) to the Ecoboost 2.0T (240+ hp)? Well obviously the turbocharged version will fall flat.

I can submit a comparison of my own. My wife's former Cobalt Sport 2.4L VVT made roughly 170 hp/160 tq mated to a 4-speed automatic. This is quite comparable to her new Cruze Premier Hatchback 1.4T/6A, which makes 153 hp/177 lb-ft and offers similar straight line performance. Both are driven on the same 30 mile commute as well as day to day errands and are just a bit under 3,000 lbs. The Cruze is 8-10 mpg more efficient.

I agree that there are many questions to ask and until they release the full report we just do not know. I for one am interested in seeing the testing used and how they match it all up. 

I can say on the auto's I have driven with a turbo motor, I have never gotten the MPG that was stated. I love my NA motors and see no need for a turbo.

[Drew Dowdell]

@cp-the-nerd hit the nail on the head. Are these engines producing less emissions and using less fuel than the engines they replaced. I can't answer the emissions part, but on fuel, my experience the answer is no.

Part of the reason is that there larger engines have kept up with technology as well. Honda and GM both have cylinder shutoff in their V6es. GM and Chrysler have it in their V8s.  At highway cruise, a Suburban is a 2.65 liter 4 cylinder.... Dead on with a 2.7 liter V6 from Ford using no boost. Likewise a Buick V6 Lacrosse is a 2.4 liter V4 at cruise.  The Mustang 2.3 Ecoboost puts out the same horsepower as the Lacrosse, but requires premium gas to do so. Yet, even being a substantially heavier car, the Lacrosse will get better fuel economy.

I do like turbos in the appropriate situation, but throwing them in everything in the name of branding doesn't seem to be working. 

[Drew Dowdell]

7 hours ago, Drew Dowdell said:

@cp-the-nerd hit the nail on the head. Are these engines producing less emissions and using less fuel than the engines they replaced. I can't answer the emissions part, but on fuel, my experience the answer is no.

Part of the reason is that there larger engines have kept up with technology as well. Honda and GM both have cylinder shutoff in their V6es. GM and Chrysler have it in their V8s.  At highway cruise, a Suburban is a 2.65 liter 4 cylinder.... Dead on with a 2.7 liter V6 from Ford using no boost. Likewise a Buick V6 Lacrosse is a 2.4 liter V4 at cruise.  The Mustang 2.3 Ecoboost puts out the same horsepower as the Lacrosse, but requires premium gas to do so. Yet, even being a substantially heavier car, the Lacrosse will get better fuel economy.

I do like turbos in the appropriate situation, but throwing them in everything in the name of branding doesn't seem to be working. 

To put it another way, the 2.3 Ecoboost is an excellent option in the Mustang, the lower weight improves balance, the engine pulls strong and performs like a V6.  However, the "Eco" part of the engine just isn't there. I've never had a chance to drive a 2.3T Mustang next to a V6 Mustang, but I suspect that in the real world (not EPA fantasy land), the V6 gets the better economy. 

[Robert Hall]

'Ecoboost' is just marketing fluff, trying to sound green...should just be honest and call it 2.3 Turbo.