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

One Lap of the Web: Porsche 959s, the Alfa Romeo 4C and the Mercedes-Benz A45 AMG vs. the BMW M135i

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. -- When initially produced to satisfy FIA homologation requirements in 1986, the Porsche 959 was the world's fastest street-legal production car.

Porsche Cayenne S Diesel: The V8 diesel Cayenne arrives

Porsche has revealed the 2013 Cayenne S Diesel with a 4.2 litre V8 diesel offering 378bhp, 626lb/ft of torque and 0-62mph in 5.7 seconds. Back in April we reported that the Porsche Cayenne S Diesel was on its way with a V8 diesel engine to take on the BMW M50d and the upcoming offerings from Land Rover with a 2014 4.4 litre Range Rover Sport seeming a likely possibility. Now Porsche has caught up and revealed the Cayenne S diesel, which gets the 4.2 litre diesel V8 with a healthy 378bhp and a very useful 626lb/ft of torque, enough to scoot the Cayenne S Diesel to 62mph in 5.7 seconds – a bit slower than the M50d, but all that torque should make it feel at least as lively.

Demise of kei cars on the horizon?

The kei car has long been a staple of the Japanese automobile industry and its car culture. Too diminutive for Western markets, the tiny cars and trucks are a strong influencer of design in Japan. Now, as The New York Times reports, the Japanese government has hit kei cars with increases in sales tax, gasoline prices and has reduced the kei car tax break introduced to make the cars popular in the first place by 50 percent.