Fuel consumption before and now

[usokpower]

It'd be nice if there was a graph with curves showing the gas mileage/hp/engine size trend over the last 20 years. That would take a lot of work though.

Here's a study that's already been done:
http://www.epa.gov/otaq/cert/mpg/fetrends/420s05001.pdf

Thanks for the link.

Well we can make a conclusive presumption that the cars today have undergone substantial changes in terms of performance but the fuel economy relatively didnt change since the 1980s.

I think they really intend to stay at that way. I think the closest car that we can really get a great fuel economy would be the honda jazz and the toyota yaris.

[niky]

It's not intention. It's the work of market forces and government regulations.

Let's go back to the 70's. Your basic "hot hatch" back then could get good MPG and great acceleration out of a 1.6 liter engine. Why? Because cars were much smaller and lighter then, and emissions regulations weren't so bad.

What has happened since then is that emissions regulations have gotten ever more stringent, meaning you get less and less power out of the same engine. Nissan's SR20DE could get 140-145 hp in the old Sentra SE-R. Due to strict emissions regulations, this trim level was banned in California. Later years saw the power go down to 140 hp. In its last application, the outgoing Nissan Serena, this engine only has 135 hp.

Same with the Mitsubishi 4G63 (which will not come back in the next Lancer... it's being replaced with the 4B11). Back in the early 90's, it produced 145 hp (NA tune) in the Galant GTi. In the current Lancer GT, it produces 135 hp (although sometimes it feels like even less).

Manufacturers are constantly battling to get more power out of their engines and more fuel efficiency, only to see these gains lost due to ever-stricter emissions and safety regulations.

Ahhh... where does safety come into this? While your common airbag and restraint system doesn't add more than 25 kilos to the vehicle, the necessity of meeting crash regulations and customer expectations regarding noise and vibration reduction means that vehicles are getting heavier.

Add to that the need to cater to the mass market, who tend to gravitate towards bigger and bigger vehicles as they get older, and lots of models have gotten bigger over the years... which also makes them heavier, as you need more crash structure to protect more space. Bigger bodies need more powerful engines to move them... which means, again, more weight.

One seeming exception to all of this is the current Corolla. Its featherweight body actually gives it great mileage and good acceleration from what is basically a puny 1.6 liter engine.

But it's difficult to say that fuel economy hasn't changed at all. If you look at economy versus utility for some models, there are a lot of models now that have much better economy than 80's models simply because more passengers and luggage can fit in their bodies than before.

Your typical 80's Lancer, for example, is much smaller in terms of cargo and passenger capacity than a Honda City. And a Honda City can get even better mileage out of its 1.3 iDSi and CVT in traffic situations than the old carburated 80's car can. Sure, an older Civic 1.4 EG hatchback could get economy almost as good, but it won't meet current emissions regulations anymore... nor does it have quite the same crash survivability as the newer car.

[mbeige]

Look at the performance of the Yaris and the Jazz, and compare it with less fuel efficient cars. If you're all after fuel economy, get a modern diesel. After all, diesel costs cheaper than gas. Light car bodies like the VW Lupo that have diesel variants will inevitably get consistenly great MPG but at the cost of performance.

Actually if you look at that PDF file again, you would say that cars have now become more efficient. If you consider performance to be the variable, then I would say they are more fuel efficient now. But if you consider the fuel economy to be the variable, then they're more powerful. So if you look at both, they're more fuel efficient, and more powerful too.

Read about this link, it mentions a car that can do 12,670 miles per U.S. gallon, but it's no ordinary fuel...can you guess what it is?

http://www.primidi.com/2005/07/05.html

Another interesting read:

http://www.40mpg.org/getinf/120105release.cfm

The most fuel-efficient cars not sold in the U.S. are almost all powered by "clean diesel," not hybrid technology. Of the 34 vehicles not for sale in the U.S. achieving combined city/highway fuel efficiency of 50 mpg or better, all but three use diesel power. (By contrast, the US EPA has ratings for a total of only five diesel-powered vehicles of any kind.) According to the EPA: "Diesel-powered vehicles typically get 30-35 percent more miles per gallon than comparable vehicles powered by gasoline. Diesel engines are inherently more fuel efficient, and diesel fuel contains 10 percent more energy power per gallon than gasoline. In addition, new advances in diesel engine technology have improved performance, reduced engine noise and fuel odor, and decreased emissions of harmful air pollutants. New low-sulfur diesel fuels available beginning in 2006 will help reduce emissions from these vehicles even more."

[pup2]

Guys ... we're all basically saying the same things, albeit in different countries/weights. Kaso wala na yata ang poster to agree or disagree.