The Chevrolet Corvette has a new-for-2027 LS6 V8, and it should be better in every way than the engine it replaces. The 6.7-liter mill has more displacement, more power, and more torque, to start. It's also an entirely new generation of engine, one that General Motors has touted as being vastly improved from the long-running 5.3-liter and 6.2-liter generation that came before.There is, however, one way that the new LS6 falls behind the old LT2. And it's one that could cost you every time you go for a drive: Fuel economy. More Power, More Displacement, More Fuel Chevrolet Corvette and fuel economy sound like they're as important to each other as the Toyota Prius and Nürburgring lap times. But we'd argue that's not entirely the case. The Corvette is an incredible machine, but in its most basic form, it has also long been about value. It delivers exotic-smashing performance at attainable prices, and running costs are a significant part of that, especially with current gas prices.The EPA has just revealed the fuel economy figures for the 2027 Chevrolet Corvette Stingray, the entry-level model in the lineup. Last year its numbers were 16 miles per gallon (mpg) in the city, 25 mpg on the highway, and 19 mpg combined. The new engine is a bit worse, dropping to just 15 city. Highway mpg holds steady at 25, but the city hit is enough to drop the combined rating to 18 mpg.Of course, your actual pain at the pump depends on how much you drive, and we suspect most new Corvette aren't serving daily driver duties. But you could be looking at an extra $200 or so per year for that extra 40 horsepower – a small increase, but a notable one just the same.Chevrolet's new 6.7-liter LS6, or 409 if you're old school, puts out 535 horsepower and 520 pound-feet of torque. The Stingray's previous engine made 490 hp, or 495 if you got the sports exhaust, and 470 lb-ft. It has the same power in Grand Sport trim, but get the Grand Sport X and you add 186 hp from an electric motor. You also get AWD, and if you really care about fuel economy, you can drive for a bit on pure electric in that one. For the record, fuel economy ratings for Grand Sport aren't available yet, so we can't do a straight comparison. Corvettes Have A Long History Of Efficiency Chevrolet The Corvette has always been surprisingly efficient, at least by the expectations of a V8-powered performance car. GM's small-block V8s deliver massive torque, and that has allowed long high gears and cruising speeds barely off of idle.The winner for the most fuel efficient Corvette dating back to 1984 is actually the C7 generation. The base-model 2014-2016 cars with a 460-hp 6.2-liter V8 and a seven-speed manual are all rated at 17 city and 28 highway. Automatics were slightly different at 16/29. From 2017 on, it dropped to 16/25 for no obvious reason.C8-generation Corvettes are the thirstiest cars. Not the base models, but the ZR1 cars with their twin-turbo 5.5-liter V8 engines. They make 1,064 hp, so it's not exactly a surprise, but 12 mpg in the city and 18 on the highway means a cruising range of just 259 miles.A basic 1984 C4 Corvette was rated to get 13 city, 20 highway with either the four-speed manual or four-speed auto. In that first year, and the first year of online EPA data, the car made 205 horsepower. That makes it by far the least efficient Corvette in terms of power-to-efficiency. CarBuzz Insight – Why This Matters: Chevrolet Even a bargain sports car owner probably doesn't worry much about fuel costs. However, this new fuel economy figure might be a bigger issue for the vehicles that don't get the new engine just yet. GM has confirmed that the 2027 Silverado (and by extension the 2027 GMC Sierra) will get new 5.7 and 6.6-liter engines based on the same new architecture.Pickup truck buyers generally cover a lot more distance every year, and for owners, the trucks can be vital to their livelihoods. Today's 5.3-liter V8 Silverado 4x4 gets 15/19 and 16 combined. A 6.2-liter truck gets 15/20, or 14/17 if you pick a version with off-road tires. That's not far removed from fuel mileage ratings of trucks 25 years ago. So even dropping one or two mpg could be a tough selling point for new Chevy V8 trucks, especially when the brand is already worried about high prices cutting into sales.