Arias Pistons 12.5:1 Compression 82mm Bore Honda B-series on 2040-parts.com

One Lap of the Web: Mercedes-Benz SLC rendered, Google Glass for the Tesla S and a rusty Datsun 280ZX

We spend a lot of time on the Internet -- pretty much whenever we're not driving, writing about or working on cars. Since there's more out there than we'd ever be able to cover, here's our daily digest of car stuff on the Web you may not otherwise have heard about. -- Last month we brought you some intriguing spy photos of a Porsche 911-fighting Mercedes-Benz coupe -- possibly to be called the SLC, or even the next SLS AMG (it's all a bit unclear at this point) -- but layers of camouflage made it a bit tough to see what the car will look like.

Citroen DS5: UK price & specification

The Citroen DS5 goes on sale in the UK in April After a public debut at Top Gear Live in November, the Citroen DS5 is ready for UK launch. Price & specs – starts at £22,400. It’s getting on for three years since we first reported that the Hypnos Concept would arrive as the Citroen DS5, and that there would be a hybrid Citroen DS5 by 2011.

For new CAFE rules, automakers place high-stakes tech bets

Game-changing 2015 fuel economy rules are forcing vehicle development teams to make high-stakes bets on expensive technologies--bets that will separate the winners from the also-rans. Not only do federal rules target a 2015 fleet average of 35.5 mpg, up from the current 27.5 mpg for cars and 23.1 mpg for light trucks; they force automakers to bet on different technology packages for each vehicle segment. Companies that do best at mixing technologies while keeping down costs will have an advantage when buyers wince at higher stickers.