Fuel consumption before and now

[usokpower]

I dont know where to put this thread but since the forum included the word "comparison" I decided to put it here. Mods, if you find this inappropriate kindly transfer this thread. Thanks.

I just noticed that the fuel consumption from the 80s and today didnt change despite the huge gap in terms of technological advancements. Most cars still average between 7-10km/litre despite the existence of CRDI, EFI, Variable Valve Timing engines, CVT, and some electronic gadgets that I am not aware of.

Even if you say that although cars get the same figures but nevertheless cars today are more effecient since it has more engine power. But the bottomline is it still has the same fuel consumption.

THe only way that I can think of to get a higher figure is to adopt unpractical and unrealistic driving practices like in the Petron blaze driving challenge.

Hangang diyan na lang kaya ang average fuel consumption ng gas or diesel engines?

[oldblue]

mas ok naman tsikot ngaun with a lot of amenities

[pup2]

Tingin ko kasi masyadong malaki ang gap ng range mo na 7-10 km/liter. If you break that into say 7-8 and 9-10 kms/liter may makikita ka namang improvement. Its not comparable to a computers speed improvement pero meron pa din.For example, nung 80's yung car ko na 7-8 kms/liter ay mitsubishi colt na 1.4 liter. Ngayon, ang katumbas noon ay halos Honda City na napakahirap pababain below 11 kms/liter ang konsumo. Yun namang car ko nung 90s na 9-10 kms/liter ay mitsubishi lancer na 1.4 liter din. Kung ikukumpara sa ngayon, ang closest siguro ay Civic na 1.5 liter (nung panahon na meron pa nun). Bukod sa mas malaki makina nung Civic, mas madali makuha ang lagpas 10 kms/liter kesa sa doon sa Lancer na nakakakuha lang ng 10 pagka bagong tune-up, service, etc.Bottomline, may improvement. Hindi nga lang earth-shattering. Also, a large part of it is offset by the slowly increasing weights of newer cars as well as heavier feet ng nagda-drive.

[redorange]

Your Km per liter is not just determined by the car you drive but by the traffic around you. Just look around you when you are driving is the traffic you encounter now the same as the 80's or even the 90's? There are more vehicles in the roads now from jeepney, bus, trucks, etc. the is more congestion in the roadways. The main difference is the cars now burn cleaner with unleaded gas as opposed to the 80's and early 90's with leaded gas used by cars. If you had the technology of today with the traffic situation of the past you'd probably get better mileage.

[mbeige]

The answer lies in more power and more efficient for that amount of power. I too thought of this and if you could just imagine:

You get great fuel economy back then, but your 0-62mph is really slow. Now, you get the same fuel economy, but your 0-62mph is much smaller with the newer engines.

If you drive at the indicated highway speed limit noon (55mph/90kph) you'll get the best MPG for long haul drives. But if you drive at the indicated speed limit these days, you actually get more.

I'll use my car as an example. It's a 1983 300D turbodiesel. It's counterpart these days is the E320 CDI/Bluetec. I get a respectable 25MPG mixed for a 24 year old car. My car's factory EPA estimates were 27city, 34highway. I have managed to get the 27mpg in the city but not yet the highway because the car was built to travel at 55mph. Above that, MPG declines.

The new MB on the other hand gets 27 city, 37 highway. I haven't tested this yet (I would kill to!) but I'm pretty sure it will get slightly below that amount because of AC usage, traffic conditions, etc.

BUT...my car gets to 62mph in 12-13 seconds. That new MB gets there half the time, maybe even less!!! And it's even faster than its gasoline counterpart!

There has to be a balance between power and fuel economy, and still satisfying emissions requirements. That's a lot to consider when you attempt to engineer a new car design! If you boost the fuel consumption a bit, emissions will suffer, and will make the car a "gross polluter" (in the eyes of EPA) and won't be marketable (if there's such a word) in other regions. So manufacturers have to design these cars to meet ALL requirements and still pass and provide years of troublefree motoring. Which leads to another consideration. With regards to environmental pollution, the manufacturing of certain materials is already limited due to environmental concerns. Imagine, if you build a very efficient Toyota Prius but you actually fail to mention that the batteries used are very harmful to the environment, how can you actually save on great fuel economy if you ruin the environment in the same process? Cheaper materials are used to build cars these days and that also inhibits manufacturers from getting great build quality. It also allows for parts to break easily. Crumple zones have to be engineered to also be pedestrian-safe, this entails the necessity to design the hood, wipers, grille and bumper to be soft enough to be safe, but hard enough for an actual car collision.

So, getting back on topic. There are a lot of things to consider with increasing fuel economy and making it still realistic for each and every customer to drive the cars. I mean, you can't always expect them to drive at 55mph/90kph all the time and know when to brake (or when not to), when to use the AC, electricals, and when to put stuff in the trunk to save weight. Tires are also another concern when fuel economy so you have to keep them in the correct pressures. All these for a soccer-mom to consider? Not really. People buy cars as transportation alone most of the time. They just want the car to get from A to B and get the EPA estimates they were told to get. That's mostly what they really care about, and the other factors get overlooked until the next maintenance period.

Ah, I wrote too long... hehe sorry I also pondered on this a long time ago and I hope I have answered the question if not provided good info on it.

[Jun aka Pekto]

I agree with mbeige. I had a 1986 Nissan Pulsar NX. While it had great gas mileage, it's 1.6L 4-cyl engine put out a puny 55 hp. Today's cars with 1.5 4-cyl engines are much more powerful (over 2x my Pulsar's) and yet has still the same or better gas mileage.

[usokpower]

I do agree that cars today are much more effecient than before. Our Mitsu L200 with 72hp averages between 9-10km/itre while our Toyota fortuner with 163hp get the same figures. Sometimes the fortuner even gets better mileage but only by a slight margin. ALthough cars today are quicker, more comfortable, includes a lot of amenities, etc. but why cant they build gas or diesel engine powered cars that can go as far as let us say 17-20km/litre?

I would like to think that 9-10 or 10-11 km/litre is the margin that car manufacturers want to stay since they keep building more powerful engines as time progresses. But if they maintain the level of engine power that we got from the 90's (corolla gli * 110hp, civic lxi * 105hp) and with the technology today perhaps or maybe we could get a significantly better fuel consumption.

Or maybe car makers are in collusion with oil producers.

[mbeige]

^^They already can, but would the common man want to buy it with its performance? Probably not...

The key is to gradually increase performance with relatively similar fuel economy. Look at the patterns!

[Jun aka Pekto]

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

[kinyo]

it is the same internal combustion engine we are using for decades ... it can only do so much even at complete combustion operation ... it is inherently a very inefficient machine and will remain that way

fwiw ... crdi technology appears to be a significant improvement and is likely to be embraced by every auto manufacturer in the future ... 20 km/li might become the new benchmark for anyone using a diesel engine

[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.