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America’s Cars Are Getting Faster and More Efficient

bloomberg.com

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Re: America’s Cars Are Getting Faster and More Efficient

#31

Post by 6stringmerc »

They have to be a lot more efficient to haul around all the extraneous shit that people have demanded be put into cars over the years. Of course it's always extreme in "Top of the Line" products like this Bentley (http://blog.caranddriver.com/it-takes-a-lot-of-wiring-to-kee...) but the trickle-down effect is inevitable. Happened with air bags, IIRC. Look how many companies are adding variations of "Auto Pilot" or driver assists.

Basically we painted ourselves into a corner. Technology and Distractions have an inverse relationship with Driver Attention and Performance. People don't like hearing that, but I don't like having to honk at people weaving into my lane because they're on their phone at 70 MPH.

Re: America’s Cars Are Getting Faster and More Efficient

#33

Post by nightski »

oneshot908 wrote: post #18
drewg123 wrote: post #11

I'm not sure that I believe their assertion that cars have gotten lighter. Perhaps the real land-yacht monstrosities have been weeded out (and replaced with SUVs). But it seems like comfort and safety concerns, coupled with more power and better fuel economy have been causing equivalent cars to become heavier (and more expensive) over time. As an example, one of my first cars was an 84 VW GTI. It weighed ~2000lbs. Tr…

My 1999 Camaro Z28: 320 HP and ~3,400 pounds My 2016 Camaro 2SS: 457 HP and ~3,700 pounds Well, half-right at least... That said, IMO that 2016 car drives like a budget Porsche Cayman while the 1999 car was a glorious tire-smoking muscle car. Ironically, I get slightly worse mileage out of the 2016 edition (22 vs 25 mpg).

Why would that be ironic? It has almost 1.5x the horsepower.

Re: America’s Cars Are Getting Faster and More Efficient

#34

Post by jabl »

tsomctl wrote: post #14
skanga wrote: post #8

I'd love to see a chart of the power/weight ratio of engines over time.

Not particularly impressive. You can make an engine significantly lighter by changing the short block from cast iron to aluminum. The only problem is long term reliability (if an aluminum block ever overheats, it is significantly more likely to destroy itself than cast iron).

My car as a cast iron engine block; alas, it doesn't have replaceable cylinder liners nor are bigger piston rings manufactured, so when the workshop managed to crack a piston they ended up having to change the entire engine. Yet another example of the throwaway society, eh... :(

Re: America’s Cars Are Getting Faster and More Efficient

#35

Post by Shivetya »

drewg123 wrote: post #11

I'm not sure that I believe their assertion that cars have gotten lighter. Perhaps the real land-yacht monstrosities have been weeded out (and replaced with SUVs). But it seems like comfort and safety concerns, coupled with more power and better fuel economy have been causing equivalent cars to become heavier (and more expensive) over time. As an example, one of my first cars was an 84 VW GTI. It weighed ~2000lbs. Tr…

Well F150s dropped a couple of hundred pounds go to aluminum. The Chevy Volt; I own the second generation; is three hundred pounds lighter.

Now if you go back twenty plus years or more before the age of crush points and advanced passenger safety systems both passive and active, yeah you can find your lighter weight cars. Cars which won't handle a head on with a car two sizes smaller.

Weight is one reason why manufacturers are loathe to commit all out for BEV, that thousand pounds of battery not only takes an hour to charge fully it weighs the same with or without a charge and imparts little range (sorry but if your range starts with a 1 or 2 its commuter range)

now take into account that many nameplates moved up in size classification. Accords certainly were not mid sized when they came out and even Chryslers minivan if not Honda's first weren't very big.

Efficiency gains are certainly there but much is lost with the way people drive.

Re: America’s Cars Are Getting Faster and More Efficient

#36

Post by squozzer »

They picked an interesting starting point for their comparisons, which was 1975, several years after the following:

1) HP ratings went from SAE gross (at flywheel with no accessories) to SAE net (at flywheel with accessories and stock exhaust) 2) Smog controls (AIR, EGR, and cats) 3) Lower static compression ratios to handle unleaded fuel

That said, computer-controlled spark and fuel, and now direct injection, makes modern cars a lot more fun if maybe a little same-looking.

Re: America’s Cars Are Getting Faster and More Efficient

#37

Post by nradov »

6stringmerc wrote: post #31

They have to be a lot more efficient to haul around all the extraneous shit that people have demanded be put into cars over the years. Of course it's always extreme in "Top of the Line" products like this Bentley ( http://blog.caranddriver.com/it-takes-a-lot-of-wiring-to-kee... ) but the trickle-down effect is inevitable. Happened with air bags, IIRC. Look how many companies are adding variations of "Auto Pilot" or d…

The sensors and actuators used in active safety driver assistance systems are light and take up very little space. Most of the extra weight comes from passive safety improvements such as stronger unibodies. Those are far from extraneous.

Plus cars are simply growing because most people prefer larger vehicles. A long drive in a tiny penalty box car is a miserable experience.

Re: America’s Cars Are Getting Faster and More Efficient

#39

Post by jabl »

Aloha wrote: post #30
kakarot wrote: post #26

If only the auto industry hadn't canned Henry Ford's efforts to mass produce cars with hemp-composite materials.[0] They would be arguably faster, lighter, more efficient, and safer than anything on the market. But, ya know. Car wrecks are good for business, and efficiency is bad for business. [0] https://www.youtube.com/watch?v=srgE6Tzi3Lg

In other words, a Trabant. Hemp is not a magic fiber, it's just able to be grown with a much lower environmental impact than cotton. Otherwise its just another fiber.

And if you're involved in a tragic crash where the wreck of your car catches fire, at least you'd die happy, eh?

(yes, I know hemp grown for fibers doesn't contain THC or whatever the active ingredient in weed is called. It's a joke, you see)

Re: America’s Cars Are Getting Faster and More Efficient

#40

Post by semi-extrinsic »

trjordan wrote: post #20

My first car crush was in high school: the 2002 Subaru WRX. It would be fine to get some souped-up monster, and high-end BMWs are always fast, but when I first saw those silly little bug eyes and the trademark blue color? God did I want one. It was weird to figure out that it only came with a 2 liter engine. Apparently turbos help a lot. It was even weirder when the 2005 STI came out with the same engine ... and a bi…

In F1 they now have waste heat recovery systems, as I understand it (please, F1 engineers, correct me if I'm wrong) in the form of mechanically decoupled turbine and compressor wheels on the turbo. The (exhaust) turbine generates electricity which it can feed either to the battery or to the compressor wheel motor (acting like a regular turbo in the latter case). In this configuration, you can also electrically spool up the compressor wheel from the battery, giving exactly zero turbo lag, and they can also recover impressive amounts of energy that would otherwise be wasted - about 1 kWh in a 90 second lap.

[For a longer while, we've had anti-lag systems on racecars that basically burn petrol in the manifold, always keeping the turbo spinning. These are horribly fuel-inefficient and destroy turbos etc. quickly.]

I sincerely hope that electrically coupled turbo systems are adopted in road cars. The recent Audi/Bentley top-end (diesel!) SUVs with electric turbos are promising in this regard, but I don't think they do waste heat recovery per se.

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