This is pointless since I could as well have checked the answers on Wikipedia before posting, but this is a forum with a great lot of car nuts. Real car nuts, not people who buy a Ferrari to drive to Starbucks (gratuitous blow below the belt
). We're not "the public", or even "the American public" (insert NASCAR redneck stereotype here). We know better.
In fact rally drivers generally humiliate drivers from other major leagues in the Race of Champions - a yearly event with drivers from all leagues, driving all kinds of vehicles (WRC, F1, go-karts, "hot hatches", GT3s...).
It's pretty obvious why: a great WRC driver is equally fast on all surfaces. A great F1 driver is only fast on tarmac. That's the reason why rally is the most demanding form of racing.
About Walter Röhrl: it might sound odd to consider him the all-time best rally driver, considering he only won 14 races and 2 WRC titles.
However, he always had to make up for an inferior car. In 1980-1983, he won 2 titles despite the Audi Quattro's superiority. When he eventually joined Audi in 1984, there was a new sheriff in town: Peugeot. His stunning 1982 WRC title is the bext example of how superior driving skill can compensate technological inferiority.
When he did not win, he was always 2nd or 3rd. That kind of regularity pays off big time over a full season.
In 1983, his team, Lancia, did not care about the Drivers' championship and chose not to enter the last race in order to save money. They had won the Manufacturers' title. Mission accomplished. Röhrl was not Italian
, so they deprived him of a possible 3rd title.
Lastly, the reason Walter Röhrl is the greatest rally driver ever is that during the mid 1980's, group B rally cars were genuine monsters (600hp with extreme turbo lag on snow or gravel...
). Kankkunen and Makinen might have won 4 titles, but they did most of their careers on comparatively tame group A (production-based 300 HP) cars.
To be fair, if Walter Röhrl is the greatest
rally driver ever, the greatest driver ever has to be Jacky Ickx.
