Variable Displacement/Cylinder Deactivation An engine’s displacement is the volume of a single cylinder multiplied by the number of cylinders. An engine capable of variable displacement changes the number of cylinders it runs on, in turn changing the effective displacement. Fuel flow to the inactive cylinders is cut, and the valves are deactivated. With fewer cylinders to fill, fuel economy improves.

pioneered the technology (in an automotive application) in the V-8-6-4 of the early ’80s, but the technology has only recently reached its full stride. Engines with variable displacement include

Hemi V-8s, GM’s V-6s and V-8s, and

3.5-liter V-6.

Turbochargers With a forced, or pressurized, intake charge like that provided by a turbocharger, an engine can burn more fuel. Think of it as shaking up a can of pop before you open it. The can is the cylinder, and the release of pressure when you open it is what produces power. More pressure means more power. This is why turbocharged engines typically make more than 100 horsepower per liter of engine displacement, a feat that naturally aspirated engines (without turbo- or superchargers) struggle to achieve.

A turbocharger consists of two fans: one in the exhaust stream (called the exhaust turbine) and one in the stream of air entering the engine (called the compressor turbine). Exhaust gases leaving the engine spin the exhaust turbine, which is connected to the compressor turbine. As the compressor turbine spins, it squeezes the air coming into the engine and increases the pressure—like shaking the pop can.

Turbochargers do not directly increase the efficiency of an engine. What they offer is big peak power from a small engine. The advantage is similar to that of variable displacement—the option for power is there, but when it is not needed, the engine is fairly efficient. However, if a turbo or two were fitted to a large engine, the power output could be astronomical.

Article source: http://www.caranddriver.com/features/08q3/five_fuel-saving_technologies-feature/variable_displacement_and_turbocharging_page_2

BMW M5 New 2011

Hi all – Reading everyone’s posts was really helpful to me when shopping for my lease, so I thought I’d share what offers I received. I ended up choosing another car, but I hope this could be helpful to others.

I currently have a 2007 A4 Quatro 2.0T Premium Plus, which I leased from Audi of Charlotte. So I started back there in negotiating a lease on a 2010…guess they don’t need any business!! They wanted to work out a deal with me based on MSRP: amazing they weren’t willing to give me at least my Audi loyalty. For a 2010 A4 Premium CVT, they ended up quoting me about $4200 down + $389/month (not including tax). 42 months/10k miles per year. No deal.

I used http://amexnetwork.zag.com/main.html to shop around a few other dealers. I highly recommend this site! It helps you drop MSRP and puts you in a great starting negotiation point.

I got a lot of great offers out of Atlanta. The best came from Gwinnett Audi:

36 month lease / 10k miles per year

Sales price on an A4 Premium is $33,050. With the Amex and Audi Loyalty the price is adjusted to $31,459.

$422.20 (incl. 5.75% NC tax)/month, total due at signing is $505.70

Best of luck to all!

Source: http://www.edmunds.com/dealerships/Audi/NorthCarolina/

2004 Audi A4 Used Cars Burlington NC