 Complete the following phrase:  The situation improved immensely when Ayrton Senna signed to partner Alain Prost at Prosts suggestion on a 3-year contract. The McLaren chassis, the Senna and Prost pairing, and finally the new Honda engines with , looked like a formidable combination. However, there were concerns after the FIA introduced a fuel regulation for the turbo-powered cars of 150 litres for a race distance. Hondas engine management team worked feverishly on the fuel consumption of the RA168E which was specially built for the reduction in turbo boost from 4.0 bar to 2.5 bar rather than upgrading the 1987 spec engine, trying to improve it in order to avoid embarrassing late-race retirements. The car appeared as-is through the season, save for a few aerodynamic revisions. The car arrived at the first race in 