Is it bad to let the transmission drop 2 gears climbing a steep grade?

A buddy of mine told me that driving on the highway in cruise that I should never allow the transmission to kick down 2 gears and rev up real high like they do on steep hills running on the cruise. I never thought it was bad as long as it didn't redline, but am I wrong? Should I kick the cruise off before ascending a steep hill you think?

He claims he's seen so many engines blow up from doing that.

 

Cruise is for long stretches of light traffic flatland IMO. My mouse motor drops 2 gears at freeway speeds on sustained, steep grades. I wouldn't maintain 5300 RPM for 5 minutes, but with my configuration and 2.7 auto combo that's the name of the game on that kind of road.

 

It's not the dropping two gears that kills a transmission, it's the heat build up while hunting for gears -- the slippage internal to the transmission while it's in between gears that causes the heat build up.

Best course of action on a steep grade is to turn off overdrive so the transmission isn't constantly going back and forth between 3rd and 4th.

 

Turn off cruise when going up steep grades.

 

I don't really think this applies to modern cars any more. Just put it in D and let the computer figure it out, cruise control or not.

 

People, these days, just don't know how to drive anymore. I'll bet when driving down a steep grade, you ride the brakes all the way until the rotors are glowing, while talking on your smart phone .

 

Wat?

 

Do this; ignore the rest.

 

^^^^^^ this

 

I also press the ECT button (left of the steering wheel) to make the shift points a bit higher - this also helps if the truck keeps trying to switch between 2nd & 3rd gear.

This only applies to automatics because of the torque convertor.

 

better to let the engine sing at a higher rpm for a bit than have the tranny hunting up and down for a gear. If the high rpms worry you slow down a bit

 

^^ this.

 

OK, I'll give an alternate viewpoint of what many are saying - $$$. I always pop cruise off when climbing a steep grade as I'd rather not hum that engine/tranny that long, but I'd also prefer not dropping down to <9 mpg so I can shave a few seconds off my total drive. Not that I have CC in my Taco, but do in my Camry. Flat roads around here are more elusive than a wife that says "Yeah, she's cute, bring her home." Lots of longish grades in both directions means CC goes off and on