Gadgetory

now first the dirty little secret of combustion engines they're not real efficient in fact your car's engine is a better heater than a motor over 60% of the gas you buy goes into creating heat and exhaust put another way next time you do one of those $75 Philips realize that about 56 bucks of it isn't used to move your car but to heat it with that depressing thought in mind let's see what's going to save fuel in cars that already burn it so inefficiently number five adaptive battery charging about a three to four percent savings here your alternator charges your battery it's driven by a belt that drags on the engine all the time that hasn't changed in the better part of a century but today new systems like BMWs EfficientDynamics only engage the alternator when you break or are coasting that means kinetic energy keeps the thing spinning as opposed to combustion energy very smart number four electric rotating accessories of five to six percent savings here talking about your power steering and water pumps your air conditioning compressor those are all little parasites driven by belts that SAP the engine electric power steering is already taking over in cars as we speak and electric water pumps you should start seeing those around 2014 now electric air conditioning compressors have the added benefit of keeping the car cool even when the engines off and that brings us to number three start/stop technology it can save you six to ten percent when you come to a stop the engine shuts down until you lift off the brake to get moving again that reduces not just fuel waste but also emissions in congested traffic this trick used to be confined only the hybrids but now it's spreading to gas engine cars Mercedes BMW Mazda Ford just some of the car makers using it in five years or so I'm willing to bet it'll be as common as a parking brake number two 8 and 9 speed automatic transmissions with a fuel savings of 10 maybe 15% if you think a 7-speed automatic is overkill here a couple of shifts behind the eight speeds are here the nine speeds are on the way like ZF 9 HP transmission first adopted by Chrysler the idea behind all of these is simple internal combustion engines have a fairly narrow sweet spot for efficiency and the more gears you have to choose from the more likely you can keep the engine in that spot before we get to number one here's the real number one saving weight this isn't one technology though it's a combination of carbon fiber parts high tensile steel frames aluminum body panels and suspension parts lighter seats and plastic everywhere when you take weight out of a car you don't just improve its fuel economy but also its acceleration its breaking its cornering just about everything except perhaps how it does in a collision with a Ford Expedition the number one fuel saving technics out there right now and has a huge future is direct injection and forced induction a couplet here up to 20 percent fuel savings direct injection delivers fuel directly into the cylinder where it's needed which believe it or not cars never actually did until very recently and forced induction like super charging or turbo charging that does wonders when it's coupled with direct injection all of this is about getting more power out of a smaller engine using less fuel look at the 2013 audi s5 for example by dropping last year's normally aspirated 4.2 liter v8 and going to a smaller 3 liter supercharged direct injection v6 the MPG went from an abysmal 14 22 to a pretty good 17 26 the car lost its gas guzzler tax uses some 600 bucks less fuel per year and still gets up to 60 in a quick 4.9 seconds for more car tech top fives like these go to CNET on cars comm we do one in every episode of the show i'm brian coulis thanks for watching