Consumer Reports rightly ponders specific fuel consumption
I've written in this space on previous occasions about the reality of specific fuel consumption (the amount of fuel needed to produce a given amount of power) in modern cars. While the Corporate Average Fuel Economy standards have remained static for the past two decades, the power output of modern engines has skyrocketed at the same time that mpg numbers have stagnated. When car-makers whine about not being able meet proposed new standards, it simply doesn't ring true because if they can make so much more power from the same amount of fuel, they can surely make the same amount of power they used to make from less fuel.
Consumer Reports noted this after attending a preview of the 2008 Mazda CX-9 which gets a bump in displacement from 3.5L to 3.7L along with 10 hp more than before. This comes with no increase in fuel consumption. When car-makers make upgrades like this one has to wonder if every car-maker needs a compact cross-over like the Rav4 that goes 0-60 in 6.7 seconds. Clearly the answer is no unless the company wants to sell product and as long as consumers keep opting for the vehicle with more power over the lesser model, CAFE standards will be pointless.
New technology like HCCI and small-displacement, direct-injected engines with turbocharging will help improve fuel economy but so far it's mainly been used just to get more power. For 2008, Cadillac is offering a direct-injected version of the 3.6L V-6 in the CTS that bumps power by 40 hp with improved economy compared to the port injected version. Why not offer a smaller 2.8L DI version with the same power and even better efficiency?
[Source: Consumer Reports]
Reader Comments (Page 1 of 1)
mike 10:34PM (10/04/2007)
As an owner of a 200hp suv, which has so much power it's scary, and I simply cannot use 90% of it, there's no excuse to put 300hp into the SAME SUV 5 years later.
There needs to be a law to make it illegal for the AutoOilIndustry to Conspire to Burn Gas.
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Jackson 12:05AM (10/05/2007)
"When car-makers make upgrades like this one has to wonder if every car-maker needs a compact cross-over like the Rav4 that goes 0-60 in 6.7 seconds. Clearly the answer is no unless the company wants to sell product and as long as consumers keep opting for the vehicle with more power over the lesser model, ..."
Yeah, that's what their customers want. Of course that's what they're going to do. Should they defy their customers and bankrupt the company?
"Why not offer a smaller 2.8L DI version with the same power and even better efficiency?"
Because their customers want the power more than the fuel savings. They're just doing what their customers are asking for. If they asked for the same power with better fuel economy, you'd have your 2.8L DI version.
Face it: they're a corporation with a duty to their shareholders to make as much money as they can and the only way to an auto manufacturer can do that is to sell whatever cars their customers are asking for.
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MikeW 12:50AM (10/05/2007)
Mazda didn't need the 3.7V6, all they needed to do was fix the axle ratios. 3.464 in the '07 and '08. The Cx-7 had 3.749 with smaller diameter tires 235/60 18 vs. 245/60 18, and weighed less (600lbs).
So the 4x4 Cx-9 should have had the shorter, and the 4x2 Cx-7 should have had the taller.
Look at Audi, the new 2.8 Audi Valvelift V6 is their 'economy' engine.
The 3.2V6 is the 'power' engine.
GM never bothered to uncork their 2.8 V6. It 'saturn-ed out' by giving it only 1 muffler in the prior CTS, and a pure regular grade fuel ignition timing.
http://media.gm.com/us/powertrain/en/product_services/2007/HPT%20Library/HFV6/2007_28L_LP1.pdf
and still 210hp, 194ft-lbs. (I like the inflection point of the variable resonance aroung 4400 or so) So throw in a real dual exhaust & premium fuel ignition timing 220 hp 200ft-lbs.(and then throw in direct injection for even more fun) If you are really into efficiency, use the smallest transmission, GM's 6L45 instead of 6L50. and use the right axle ratio 3.91 will do.
and Toyota is holding the RAV4 back, 3.08 axle ratio for 4x2 & 4x4, because they use the same axle ratio for the 4x2 & 4x4 Lexus Rx350 3.291, instead of 3.478.
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Scatter 4:44AM (10/05/2007)
The "it's what our customers want" argument is not a valid defence.
The car manufacturers have been ramming aspirational images of these overpowered cars down our throats for the last 50 years so of course it's what the consumer thinks that they want or need (when of course in reality it's the last thing they need - overpriced, dangerous, environmentally damaging)
All of a sudden when it comes to lightweight, efficient cars, advertising and marketing campaigns seem to stop working according to these companies and they start whining that it's their customers being difficult.
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Jackson 12:40PM (10/05/2007)
If you were a car manufacturer and your customers already thought they wanted or needed overpowered cars, you'd have an easy sale on your hands if you just made them overpowered cars. Why would you go to the trouble of starting up a marketing campaign for greener cars in contradiction to the rest of the auto industry when you'd face an uphill battle? The only reason I can think of is if you were trying to fit into a niche market by explicitly being different. If you take that route and complain that your customers are being "difficult", perhaps it's because you're not giving them what they want, regardless of why they want it. Not everyone wants what's good for them- look around at the supermarket some time and that'll become quite plain to you.
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Jackson 12:42PM (10/05/2007)
Sorry I posted that three times. I didn't know subsequent posts didn't give you a "You did it!" banner and an e-mail and didn't check. Can an admin please remove the duplicate posts? Thanks.
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Bill Siuru 10:39PM (10/07/2007)
High specific fuel consumption is like money in the bank. Advancing technology to get higher power outputs to satisfy current buyers' preferences means the technology will be ready to easily adapt it to getting high SFCs by downsizing engines when buyers start demanding more fuel efficient vehicles, such as if gasoline jumps to $5 a gallon.
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Nick 6:03AM (10/15/2007)
I don't know about the US, but over here in Europe car manufacturers are actively working to introduce environmentally friendly models. Of course at the same time they are also producing ever more powerful and heavy models as well, so leaving it to the consumer to have a good conscience.
In my view there is no such thing as a company with a good conscience and sense of communal responsibility - all the do is try and make the most money as possible by responding to whatever instinct their customers possess - whether a desire to be environmentally friendly or a desire to thumb their noses at other people. There will always, sadly, be both people who care about the overall health of the society of which they are a part AND people who only care about their own narrow self interests.
Of course ultimately the only way of moving people's actions towards the former is to legislate, which is perversely anathema to the latter group. But then that's often what has to happen when people behave in an anti-social way - pretty much all legislation is designed to keep people's behaviour within societal norms, whatever they happen to be at any point in time.
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