http://www.dakar.com/dakar/2014/us/s.../workshop.html
Diesels may be universally considered the best choice to win the Dakar, but the last car makers to throw their hats into the Dakar ring, Toyota and Ford, both fit their cars with petrol engines, a decision guided by reasons other than raw performance, most notably the need to bring down costs.
"I'd have chosen a diesel if I had an unlimited budget", admitted Bernd Wellmann, the engineer behind the Ranger, Ford's new machine for 2014. "3-litre turbo diesels provide a humongous amount of torque, unlike petrol engines, which deliver a much more linear acceleration. This gives them an edge on all types of courses, which is much more decisive than raw performance. On the downside, this tech is extremely delicate and, therefore, fragile. If you want to avoid a breakdown in a race like the Dakar, most importantly you need to change the injectors every two to three stages, which sends operating costs through the roof. Our 5-litre petrol V8, in contrast, is very simple and robust, so if all goes to plan we aren't even going to touch it during the race. Therefore, the decision to go with petrol was mostly a financial one."
Financial in every sense of the word, as explained by Glyn Hall, the Team Principal at Imperial Toyota, which last year finished second with Giniel De Villiers. "True, the rules as they stand now are more biased towards diesels than towards petrol engines, which have a lower inlet restriction, so if I had been given a choice I would have taken a diesel. However, the South African off-road championship is every bit as important to Toyota as the Dakar, as South Africa is the biggest market in the world for pick-ups. But diesels are not allowed in this championship?Our petrol engines are a handicap, which is why we decided to swap them for the best engines in the Toyota range, but we also put a huge amount of work into the chassis and the suspensions to compensate for this disadvantage."
St?phane Peterhansel, the last man to win the Dakar with a petrol engine (2007), now at the wheel of a diesel-equipped Mini, confirmed that drivers also feel the superiority of diesels. "At the beginning, the surprising thing about diesels is that they deliver all of their power straight away, at low revs, and that you need to stay within this low range to make the most of the engine, unlike petrol engines, which you normally keep at very high revs. You've got to get used to it, but it only takes a few hours. The torque of diesels is head and shoulders above that of petrol engines, especially in our sport, where torque is of the utmost importance. This gives them an edge on all sorts of terrains. So, even if the rules change, I'd say that diesels remain the most powerful weapon in rallies." If you can afford them, that is?