Car Tech forum: Where is the innovation when it comes to car engines?

It is not like there have not been significant advancements in many parts of the current cars of those 10 or 20 years ago but when it comes to gas mileage it basically gets down to physics.

Yes they can make a car that will get much better mileage but only with trade-offs that until recently have only been marginally accepatable by at least US consumers.

Taking the hybrids out of the mix, there is really only a few factors you can mess with the increase mileage in a gas engine based car and the biggest is the weight of the car or HP of the engine.

Making the car lighter you can use a smaller engine and thus less gas, however at about 40 MPG the trade offs get pretty significant.

Most of your gas when you are going over 35-40 mph is going against wind resistance on a flat road, so making the car lighter offers less and less. Making them more aerodynamic tends to make them smaller and often very ugly (odd how jets tend look cooler the more aerodynamic they are and cars uglier)...

There are some new tricks like how the fuel is injected, deactivating cylinders once you are at cruising speeds but these tricks tend to introduce other issues, like reliability.

So if buyers are willing to buy cars that can fit 2 people tops in comfort, are pretty ugly by current standards, have very poor accelaration, and a top end of 60-70 MPH with no head wind, and they load it with every gas saving trick in the book you can end up with a car that might get even 60-70 MPG and that costs 40,000-60,000 bucks, the problem is there is no market for a 40K ugly 2 seater...

So there is really one area in auto advancements that has pretty much hit the wall with technology, but so many other things have come a long way, my current car has built in GPS, bluetooth that senses my phone as I get in and auto-links to it, the GPS has traffic / cogestion avoidance (works ok where there is good data), it has side, front and lower air-bags, keys you can't lock in by mistake, auto-dimming rear-view mirror, USB connection, MP3 player connection, sat radio, anti-skid, auto traction control, On-Star with auto diagnostics and calls for help when the air bags are deployed, seats and mirrors that remember where I like them and the list goes on and all this in a car in the 30K range, what is amazing is most of these features can even be found in under 20K cars.

So I have to put it at laws of physics and consumer desires, most people want a car with reasonable power, enough safety features to make them as safe as possible, not ugly, air conditioning, power everything and you just can't have it all.

You bring up many excellent questions. In addition to the great replies from the other posters, one other large influence has been the bill of sale that has been given to the consumer. By this I mean the advertising that has influenced our car buying habit. For decades, the car advertising has focused on the message that sells this message: "Get of my way! I'm driving my huge, gas-guzzling monster that will eat your puny underpowered car if you don't move." Even though many car ads now try to sell fuel mileage, look how many car ads still try to sell the old message: BMW, Lexus IS, Mercedes and Audi all base a lot of their advertising on racing through the streets, beating the other drivers, plowing through corn fields and a little pillage and plundering.

On the other hand, my 2002 Acura CL-S gets 29 mpg on the highway, and it has 260hp. Not bad considering.

Speaking of nothing innovative, why do many American cars still use the old pushrod engine design? Inefficient compared to overhead cam designs. Does it cost more money to make overhead cam engines? Yes. But screw the American car-buying public. The car companies want to make money, not save gas.

Engine technology has advanced significantly in just the past few years. But, the problem doesn't lie in the engine. The fact is cars are just heavier with more creature comforts, safety equipment, and emissions hardware.

So, the 2900-pound 2009 Honda Civic EX is about 32-percent heavier than the 2200-pound 1992 Civic EX. But at 34 highway mpg and 41 highway mpg respectively, there's only a 17-percent deficit in fuel economy. Pound for pound, I'd say the 2009 engine is more efficient.

In the computing world, software scales with hardware. Today's programs require the more powerful hardware, because they're more complex. I'm sure there was a time when you never thought you'd fill up that 40MB hard drive, but that's just one episode of a podcast these days.

To the same extent, today's vehicles have to carry around so much more equipment and weight, that the actual gains in efficiency are hidden from the MPG rating.

But your question is a good one and I'm glad you asked it. I just finished ranting over on the Car Tech blog, if you care to hear more of my thoughts on the subject: http://reviews.cnet.com/8301-13746_7-10263945-48.html

Don't expect much from ANY car marker, foreign/domestic, they're all the same.

There have been smaller vehicles, mostly in Asia/Europe for DECADES that get 50mpg!

There will soon be "diesel hybrids" that will get nearly 100mpg...

Vehicles have only wasted technology for decades, lighter weight, more plastic and at the same time increased horsepower...

Unless you're hauling a trailer,etc you rarely need over 200hp!

Seeing so called "green" machines out now...well, they're about as green lead batteries that MUST be recycled in 100,000 or so...

MANY little econo boxes will NOW get over 40mph...

I get upset seeing so called "green tech" wasted by jacking up the HP, instead of trying to get better fuel economy!