but fragile; the restrictions were relaxed with the intent of permitting Buick-like engines to use stronger but still production-like blocks – the Menard engine based on the Buick took this approach, as did the unsuccessful Greenfield V8. Ilmor realized that this provided scope for a completely new pure-bred racing engine – it would need to retain pushrods, but could be designed specifically for the requirements of the Indianapolis 500, and in strict secrecy schemed a completely new V8 engine which was approximately more powerful than the Cosworth XB and Ilmor 265D opposition. Team Penske's cars were by far the fastest at the 1994 Indianapolis 500, and Al Unser Jr. won the race, with Emerson Fittipaldi also figuring strongly until an accident on lap 184. The loophole was closed for 1995, and Penske, a year behind on development for Indy, failed to qualify their 265D-powered cars for that year's 500. For 1995 the 265D V8s were rebadged Mercedes and continued to be highly competitive, with Al Unser Jr. finishing runner-up with four wins. Rahal-Hogan Racing joined Penske as major teams, as Bobby Rahal collected five podiums to finish third in the overall standings. In 1996, Penske's Unser Jr. finished fourth, Rahal seventh and his teammate Bryan Herta eighth, with neither collecting wins. In 1997, Unser Jr. had a poor season, whereas Penske teammate Paul Tracy claimed three wins but retired in the last five races to finish fifth in the standings. PacWest drivers Maurício Gugelmin and Mark Blundell claimed four wins combined and finished fourth and sixth in the standings. Forsythe driver Greg Moore got two wins and three second places, but retired in eight races and finished seventh. After the CART-IRL split, Mercedes gradually lost interest in American racing and left CART after the 2000 season. Ilmor continued working in the United States on the Oldsmobile Aurora V8 for the IRL Penske entries. In 2003 Honda partnered with Ilmor on the Honda Indy V8 engine between 2003 and 2011 for co-assembling, preparation, tune-up and maintenance. At the conclusion of the 2011 season, Honda discontinued their partnership with Ilmor subsequently moving all design, development and production in house without any third-party tune-up partnership to HPD, for the 2012 Honda Indy V6. In 2012 Chevrolet returned to the IndyCar Series, partnering with Ilmor on the Chevrolet Indy V6 engine program and supplying free engines for Team Penske and rest of Chevrolet-powered IndyCar