May 19 (GMM) Former grand prix winner turned NASCAR driver Juan Pablo Montoya has warned his American rival Kyle Busch about getting too excited about a forthcoming opportunity to test a formula one car.



Busch, a NASCAR frontrunner, revealed that he is in talks with Toyota to try the Japanese manufacturer's F1 single seater this winter, and he also refused to rule out making a full switch to the premier class of open wheel racing.



But Montoya, who was disillusioned with F1 as he moved to American stock cars in the middle of the 2006 season, warned Busch that lining up a F1 test may be more complicated than he believes.



The Colombian said there is a difference between a demonstration test and a "test for real".



Back in 2003 at Indianapolis, NASCAR's Jeff Gordon tried Montoya's Williams for a publicity stunt prior to the US grand prix.



Montoya recalls: "The car had no rpms. I told them, 'You can't do that' -- I actually convinced them to put in all the rpms like we normally would when we race it.



"Jeff did really well actually. We were very impressed. But going from a demonstration to an actual test is a big difference."



Montoya believes it will be impossible for Busch to go straight from racing predominantly on NASCAR's ovals to a "proper" F1 test.



"The first problem is your neck. You need to train for months to be able to hold it up," he said.



"They give you a day or a half a day, but you're not going to do anything and nobody is going to look at you."



Montoya recalls his first formula one test, when he was a full time hopeful racer in the F1 support category at the time, F3000.



"I trained for two and a half months non-stop. I had equipment against a bed and I could move the bed with my head.



"When I went into a formula one car, I couldn't do five laps in a row," he added.