What happens if you shift from "drive" to "neutral" while in cruise control?

Dear Car Talk

Dear Car Talk | Nov 01, 1998

Dear Tom and Ray:

What would happen if you suddenly thrust your shifter from Drive to Neutral
while the car is on cruise control? Does it screw up the transmission at all? I
want to try it but I am scared that it will mess up my car. -- Dave

TOM: You're such a chicken, Dave! Fortunately, we here at Car Talk Laboratories
are at your service. Since we test drive all kinds of cars that don't belong to
us, we're the perfect people to answer this question for you. So we went out in
the car we happen to be test driving at the moment -- a Chrysler LHS -- and
tried it.

RAY: I should point out to those considering the purchase of this car that the
LHS was a very nice vehicle; powerful, smooth, nice looking ...

TOM: Wait. Did you say "was"?

RAY: Actually, here's what happened, Dave. We set the cruise control at about 50
mph and then popped the shifter from Drive into Neutral. The engine speed
climbed a measly 200 or 300 rpm, and then the cruise control disengaged. We
tried it several times, once while climbing a hill, and each time the cruise
control automatically shut itself off before the rpm could climb much at all.

TOM: We don't know if all cars are this smart, or how long cars have been this
smart. But we can say with authority that the engine will not rev out of control
when you do this on a 1999 Chrysler LHS.

RAY: We don't want to encourage anyone else to try this. But if you happen to
borrow your brother-in-law's late-model Mercedes, and accidentally push it into
Neutral while in cruise control, let us know what happens, OK? (We're collecting
data in the interest of science, of course). Just contact us in care of this
newspaper, or by e-mailing us through the Car Talk section of cars.com.

Get the Car Talk Newsletter