The SLR was just the first shot: Mercedes-Benz and McLaren are beyond planning stages for a mid-engine, V8-powered supercar with sights set on Ferrari’s 360 Modena and Ford’s GT. The project car—though only in its formative stage—has a dedicated group looking into its engineering, manufacturing, sales and marketing feasibility, and is codenamed P8. If given approval in the coming months, P8, which would slot between the robust SL65 AMG and the SLR McLaren, could be on the streets testing by late 2006 and in showrooms by late 2007

The P8, depicted here as an artist’s rendering, is officially only a concept. Clearly, management from both Mercedes-Benz and the McLaren Formula One super team would like to put a car like P8 into production. “Yes, we are looking at a mid-engine road car,” Mercedes boss Jürgen Hubbert told AutoWeek last week. “But there is no decision on production.” Before production can happen, M-B and McLaren board members must give P8 unanimous approval. What gives credence to the likelihood of P8 seeing production? News that ultra-performance car guru Neil Hannemann, the engineering mind behind the Dodge Viper, Saleen S7 and the Ford GT, left the friendly confines of Ford in Dearborn Jan. 31 for a job as engineering director at McLaren. P8 also makes smart business sense. The SLR is built in the new McLaren Technology Center in Woking, England, a reported $300 million investment already made by both Mercedes and McLaren. Only by expanding the model product lines of this collaborative effort can that investment be amortized.

There is also ego at stake—M-B and McLaren compete with Ferrari in Formula One on racetracks around the world and want to take on the Italians in the performance street car arena. Perhaps another spur in the side to do this car is knowledge that rival Audi is at an advanced stage with its own mid-engine supercar, the Le Mans, using the Lamborghini Gallardo underpinnings (AW, Feb. 16). Though many specifics of the program remain speculation, some of what we know about the direction of both Mercedes and McLaren opens a window on what such a sports car could be like. Why mid-engine? “If you see the competition in the segment, they are only mid-engine,” says Hubbert. “In McLaren and especially (McLaren’s) Gordon Murray, we have vast experience with mid-engine cars.” Hubbert stressed the Mercedes supercar bears no relationship to the mid-engine ME Four-Twelve concept shown by Chrysler at Detroit. Mercedes engine-tuner AMG merely provided the 850-hp quad-turbo V12 for that concept, which Hubbert doubts will see production.

The high-tech SLR, with its 0-to-60-mph time of 3.7 seconds and 204-mph top speed, has proven both companies can compete in the supercar arena. However, this new mid-engine contender is a tougher assignment, not least because it must be built to a tighter budget and with an eye toward larger sales volumes than the targeted 500 annual build rate of SLR. This is not the first mid-engine road car Mercedes-Benz has considered. The striking C112 concept back in 1991 nearly made it to showrooms but was abandoned due to a downturn in the world’s economy. Also, the company’s CLK GTR was built in small numbers in 1998 to satisfy the FIA’s sports car regulations, though it was very much a race car modified for road use. In McLaren, Mercedes-Benz has a partner that knows well how to apply mid-engine design to road performance. The firm’s celebrated F1 road car may be a decade old, but few would argue it still ranks as the most accomplished supercar ever placed into production. These illustrations reveal how the baby M-B McLaren supercar could look, though wind-tunnel testing will undoubtedly change the package by the time it appears. Chances are a convertible will get the nod, insiders say.

It is reasonable to think P8 will use the same lightweight carbon fiber monocoque construction as the SLR, and incorporate features such as Mercedes’ Pre-Safe early warning system that triggers safety systems in the event of an impending crash. Engineers are striving to keep weight to 3000 pounds, or close to that of the 360 Modena and Gallardo. “Anything lower would be utopian, given the stringent crash standards the new car will need to adhere to, both in Europe and the U.S.,” said an AutoWeek source. The ME Four-Twelve beat this weight target with similar equipment and a bigger engine but no price target. Expect serious attention to weight distribution to maximize handling, with 42 percent front and 58 percent rear weight bias the likely target. We know Mercedes and Michelin are developing a two-compound tire that could make it to P8. Given M-B’s penchant for high-tech gadgets, the P8 is likely to employ the latest in electronic driver aids, too. AutoWeek can reveal top-secret details about the P8’s powerplant. Codenamed M156, it is an all-new normally aspirated 6.3-liter V8 that is also destined to power future AMG versions of the E-, CLS-, S-, CL- and SL-Class cars. The aluminum-block unit is based on Mercedes’ M273-designated four-valve-per-cylinder V8 due out next year, an engine that develops a reliable 500 hp on the engine dyno, say highly placed sources. A twin-turbocharged version that churns out a mammoth 700 hp is in early development, though that mill has not yet received the production green light. The M156 is being developed under AMG engine boss Rolf Zimmermann, who is the mastermind behind the 367-hp normally aspirated and 500-hp supercharged 5.4-liter V8 powerplants in AMG models now. Zimmermann also developed the 555-hp 7.3-liter V12 engine that powers the Pagani Zonda S. Mystery still surrounds the gearbox choice for the new car. All of Mercedes’ recent performance cars—SLR included—get a beefed-up automatic transmission that runs the company’s so-called Speedshift electronics, which make for quicker gear changes.

Sources tell AutoWeek the most likely scenario is a reworked version of the new Mercedes 7G-Tronic unit. With torque converter lock-up on each of its seven forward gears, and electronics that allow it to skip ratios on kickdown, it could turn the monster output into scintillating performance—though without the tactile feel of a manual like those in the 360 Modena and Ford GT. The torque limit for this gearbox is well within what the V8 engine could produce. As the car still awaits a production green flag, there is no firm on-sale date for P8. Still, insiders hint 2008-model-year examples will hit the road by the end of 2007—or just 46 months from now. We are told the business case for a mid-engine supercar centers on annual global sales of 800, which seems low; in fact, flexible assembly methods can allow production to increase to around 1500 a year if necessary. And the price? Positioned between the SL65 AMG and the SLR, industry analysts predict a price tag for the two-seater of around $200,000—a slight premium over the current 360 Modena and a healthy $60,000 more than the $140,000 Ford GT. Still, that is a fraction of the $1.2 million a used McLaren F1 will cost now.