We have proof that the 2013 Lexus ES will arrive with a hybrid option.

Our spy photographers have just sent us the first images of Lexus' upcoming 2013 ES sedan. Although camouflage still hides most of the car's exterior, a single interior shot has revealed the ES' secret weapon.

A close-up of the ES' gauge cluster reveals a tachometer that appears to have the words 'Charge', 'Eco' and 'Power', indicating that this particular prototype is for an ES Hybrid. That's big news for Lexus' best-seller as a hybrid powertrain has thus far been reserved for the ES' lesser platform mate, the Toyota Camry.

If the Camry Hyrbid's powertrain carries over unchanged, we can expect a 2.5L four-cylinder engine mated to an electric motor providing a combined 200 horsepower. The Camry Hybrid achieves 43mpg in the city and 39mpg on the highway, netting a combined average of 41mpg.

Although a hybrid version of the Camry has been on the market for several years now, the ES has maintained its V6-powertrain in the name of upholding Lexus' premium brand image. However, cylinder count in no longer synonymous with prestige, allowing Lexus to launch a four-cylinder hybrid version of the ES sedan.

No word on when we might see the 2013 Lexus ES in the flesh, but we wouldn't rule out the upcoming Chicago or New York auto shows.