Someone told me it's ok to shift going downhill. but isntructor says no.

This reminds me of a time I was going down a grade in 5th gear. It was most likely Flagstaff. My then wife wanted to get off at the next exit so she could use the bathroom behind some bushes. I started slowing down one whole freaking mile before the exit and I still barely managed to stop at the bottom of the exit ramp. Scary stuff, going downhill.

 

Been there, lived that.... But that....will get you thinking. And you'll think some more when you make it down, and you see the grass and the guard rail all banged up with skid marks. COM'ON SuperTrucker!

 

For the most part, your instructor is right. It's a VERY risky act! With enough experience, it's an acceptable risk. But it takes years to be able to intuitively KNOW what speed/rpm/gear you need. Having to think it through while one's freewheelin is a quick way to lose it an become a statistic.

 

Way ,way back they taught me to go down a hill one gear lower than going up, dropping a gear before heading downhill. I have actually seen drivers set the brakes on fire smoking them after missing a gear going downhill. That might be who is telling you to shift downhill.

 

What is this "double down"? I stop in Mesquite, Nv. sometimes and play blackjack and double down whenever possible (triple down is against the house rules, though) but I've never heard of it in regards to driving. Could you possibly mean "double clutch"?
rx