Top 10 Fast and Frugal Machines

Jaguar has recently worked toward lowering the weight of its vehicles to boost its performance standards. The Jaguar XK Coupe is a shining example of that philosophy.  For the size and luxury of this vehicle, it's unique to see a curb weight below 4,000 pounds. Due to extensive use of aluminum construction, Jaguar has helped keep the XK as svelte and sexy as a fashion model. The XK features automatically adjustable suspension and heated and cooled seats to keep everything smooth and comfortable. The particular example we are recommending is the well-equipped Base model. If you move toward the Supercharged version or XKR, you obviously will get more power while sacrificing some fuel mileage.  However, the Base seems to hit the sweet spot of having fun without maxing out your gas card.

Power-to-weight ratio: 0.102 hp/lb.  
Engine horsepower: 385   
Curb weight: 3,770 lbs.
Fuel Economy (city/hwy): 16/24 MPG
MSRP: $82,150

A definite surprise on this list is the Infiniti M56. Infiniti is not particularly known for building fuel efficiency into its performance. But with a powerful 420-hp engine pushing around just over 4,000 pounds, you can have a luxury sedan that can blast past most everything on the road. Infiniti has added direct injection to the 5.6-liter V8, which boosts fuel economy by allowing the engine to run leaner. Inclusion of a 7-speed automatic helps keep the engine at optimum efficiency regardless of speed. The flagship Infiniti even has a better power-to-weight ratio than the sportier G37 Coupe, with just barely less fuel economy. If Infiniti keeps pushing their M in this particular direction, people may soon consider it as a performance alternative to something like the BMW M5 or Mercedes-Benz E63 AMG.

Power-to-weight ratio: 0.104 hp/lb.
Engine horsepower: 420  
Curb weight: 4,028 lbs.
Fuel Economy (city/hwy): 16/25 MPG
MSRP:  $57,550

With the recent re-launches of the Chevrolet Camaro and Dodge Challenger, the modern muscle car era is definitively upon us. In contrast, the Camaro's huge 426-hp V8 engine delivering 19 combined MPG may be sounding the death knell for old muscle cars. Even two years ago, most people wouldn't have guessed a new powerful muscle car with admirable fuel efficiency would be coming out of Detroit; yet, there it sits. The automatic transmission-equipped Super Sport has less horsepower (26 less, to be exact) but adds cylinder deactivation to offer even better fuel economy. The 6-speed manual achieves the same fuel economy despite having more power. Whatever the formula, it makes owning a modern muscle machine that much more enticing. Now where is that turbocharged Firebird?

Power-to-weight ratio: 0.110 hp/lb.  
Engine horsepower: 426 (MT); 400 (AT)
Curb weight: 3,875 lbs.
Fuel Economy (city/hwy): 16/25 MPG
MSRP: $30,945

For some time, the Corvette has been the secret weapon of performance matched with fuel economy. Like the previously mentioned Camaro, the Corvette capitalizes on the massive torque of the 6.2-liter LS3 engine and some considerably tall gearing to crank out a miserly 26 highway mpg. That would be good even for a V6, and is outstanding for a V8 putting out 430 hp. The Corvette's trim weight and slippery aerodynamics also play into the equation. Both the Base Corvette and the Grand Sport Edition manage a respectable 19 combined mpg in the EPA's test cycle. Curiously, the 6-speed manual transmission models get slightly better fuel economy than the automatic transmission models. It's not the highest MPG on the list, but the Corvette does come in tops in performance.

Power-to-weight ratio: 0.134 hp/lb.  
Engine horsepower: 430  
Curb weight: 3,208 lbs.
Fuel Economy (city/hwy): 16/26 MPG
MSRP: $48,950

Who would have thought that by halfway through the list we would have three American autos? The Ford Mustang is a perfect example of how American car manufacturers can make alternatives to gas guzzling SUVs. Although the V6 'Stang gets great gas mileage -- 26 combined -- its 300 hp isn't quite enough to put it past our 0.1 hp/lb. performance target. However, with power-to-weight numbers that best the Porsches, the V8 Mustang GT defines affordable performance. Its new 5.0-liter engine uses an aluminum block and heads, lightweight composite intake manifold, and variable valve timing to get the job done. The 2011 Mustang finally brings 6-speed manual and automatic transmission choices, which return better highway mileage. Ford also added electric-assisted steering to eliminate the power drain of a belt-driven, hydraulic system. Muscle cars for the common man don't get any better than this.  

Power-to-weight ratio: 0.114 hp/lb.  
Engine horsepower: 412  
Curb weight: 3,603 lbs.
Fuel Economy (city/hwy): 17/26 MPG
MSRP: $29,645

The Nissan 370Z runs mid-pack on our list by barely meeting our performance goal, but still exhibiting strong fuel economy in a fun, stylish package. The track-focused Nismo 370Z manages slightly more power and only gives up one combined mile per gallon.  Chalk that up to different aerodynamics and engine tuning, we guess.  Either way, the Z has always been a fun, frugal alternative to the Porsche Boxster or Corvette.  It has heritage, racing pedigree and arguably the slickest manual transmission on a sports car with the SynchroRev Match feature.  This is one car that really helps a driver go from zero to hero, and helps keep your gas budget from taking your savings to zero.

Power-to-weight ratio: 0.102 hp/lb.
Engine horsepower: 332
Curb weight: 3,269 lbs.
Fuel Economy (city/hwy): 19/26 MPG
MSRP: $31,710

The current 911 Carrera has the third best performance figures on the list, and the fourth best fuel economy numbers. Quite impressive for a vehicle that many consider a fundamentally flawed design (being rear-engine and all). Thanks to secret magicians that pore over every inch of the iconic 911, and the massive amounts of motorsports experience acquired, Porsche can remove weight, and add power and fuel economy with the best of them. The 911 showcases style, performance, handling, sound and luxury with fuel economy just a tick off of a V6 Camry or Accord. Porsche really is the practical owner's sports car. The 911's dual-clutch PDK transmission has seven gear ratios, allowing an extra tall top gear for maximum highway mileage. Combine that with sophisticated engine management and direct injection, and you have a recipe for impressive efficiency. Honorable mention goes to the 480-hp 911 Turbo that still squeaks out 17 city/ 25 hwy mpg figures.

Power-to-weight ratio: 0.112 hp/lb. (Carrera); 0.108 hp/lb. (Carrera S)
Engine horsepower: 345 (Carrera); 355 (Carrera S)
Curb weight: 3,075 lbs.(Carrera); 3,295 lbs.(Carrera S)
Fuel Economy (city/hwy): 19/27 MPG (Carrera); 19/26 MPG (Carrera S)
MSRP: $77,800 (Carrera); $88,800 (Carrera S)

To own a Lotus Elise or Exige takes a certain kind of person. Colin Chapman introduced the legendary mantra, "To add speed, add lightness," to Lotus at its inception. That belief has led to the marginally insane creation of this oversized go-kart with a Toyota powertrain. Fuel economy and engine reliability are two strong allies that you must enlist to get yourself over the rational hurdles to owning such an impractical sports car. The Elise is 2,000 pounds lighter than the heaviest car on the list (the Infiniti M56) and the Exige has the second-best power-to-weight ratio. Very extreme performance for a car that gets 20 miles-per-gallon in the city. The Elise utilizes chemically bonded aluminum to create its super-rigid chassis. The no-frills Elise does without power steering, power seats and many typical passenger car amenities. Easily the closest things to driving a racecar on the streets, the Elise and Exige have hardcore charm while still offering enviable gas mileage.  

Power-to-weight ratio: 0.109 hp/lb. (Elise SC); 0.116 hp/lb. (Exige S 240)
Engine horsepower: 218 (Elise SC); 240 (Exige S 240)  
Curb weight: 2,006 lbs. (Elise SC); 2,077 lbs. (Exige S 240)
Fuel Economy (city/hwy): 20/26 MPG
MSRP: $47,250

The Porsche Boxster S and Cayman S share the number two spot on the list because they are basically the same car. If the Cayman had come first, maybe the Boxster would simply be the Cayman Roadster. Semantics aside, both of these fabulous cars max out performance and fuel economy, giving hope that fossil fuel-burning performance cars won't become the dead dinosaurs that they have historically consumed. The current 3.4-liter flat 6-cylinder engine features high compression with direct injection featuring triple injection points. Again, as in the 911, the Porsche PDK transmission allows maximum flexibility between performance and fuel efficiency. While both the Boxster and Cayman are highly customizable, add too many options and you will see jaw-dropping price jumps.  However they're equipped, both are admirably fuel efficient and offer arguably the best driver/vehicle connections available on the market today.

Power-to-weight ratio: 0.104 hp/lb. (Boxster S); 0.108 hp/lb. (Cayman S)
Engine horsepower: 310 (Boxster S); 320 (Cayman S)  
Curb Weight: 2,978 lbs. (Boxster S); 2,976 lbs. (Cayman S)
Fuel Economy (city/hwy): 20/29 MPG
MSRP: $58,000 (Boxster S); $61,500 (Cayman S)

It wasn't a foregone conclusion that the Tesla Roadster would be at the top of this list. Originally, the Tesla Roadster only produced an equivalent of 248 hp, making it too pokey a performer to deserve consideration. After an electric motor upgrade in 2009, it now makes the equivalent of 288 hp in its carbon fiber-encased 2,723-pound chassis.  With a range of around 240 miles on a single charge, the Tesla Roaster is no city car. Factor in the 0-60 mph acceleration of 3.9 seconds and you have one of the quickest cars on the streets. The Roadster's 3-phase AC induction motor can spin up to 14,000 rpm while driving the high-tech single speed gearbox. Not only is it a powerful motor, but it weighs a scant 115 pounds. Energy is stored and delivered via 6,831 lithium ion batteries packed into a sophisticated battery pack unit. Additionally, regenerative braking allows the Tesla to recycle some of its scalding performance.

Power-to-weight ratio: 0.106 hp/lb.
Engine horsepower: 288  
Curb Weight: 2,723 lbs.
Fuel Economy: estimated equivalent of 135 mpg
MSRP: $101,500