Driving With Tranny In "m" (manual)

[kalashluvr]

Hello, I'm new to the forum and own my first Chevy Silverado. I have the 5.3 with 3:08 rear gear, and the 6 speed tranny. I hardly even thought about the rear gear when test driving and purchasing (because I was so impressed with everything else)!!

 

I have a 50 mile round trip commute each day, and there are points in my commute where I pull hills that are just steep enough to kick the tranny down to 5th gear and then go back to 6th a few times, before I clear the crest of the hill.

 

What I'd like to know is: Will driving with my shifter in the "M" position, and bumping the gear from 6th, to 5th, and back to 6th, do anything detrimental to my transmission?

 

I've had a mechanic tell me before that it wasn't good to drive my Toyota Highlander around in "sport shift" mode all the time, and I'm wondering if the truck will be the same way.

 

Also, I'm very surprised though that the truck does so well in the city with the gear. I think that the 3:42 would have probably been the best choice for drivers with commutes that are mixed with hills and flat areas. I don't ever tow anything with the truck. I think that the 3:08 will definitely get better mileage on the interstate, but I think the 3:42 would get better mileage if the commute is in 45-55 mph zones with slight inclines......45-55 with the 3:08 (on level ground) gives veeeeeeery low RPM....

 

So, can I drive in M, or is that just for occasional use?

[Matt_]

That's exactly why GM put the 'M' mode there. Use it

[stefman722]

X2!!

[Zembonez]

You have a 3.08 rear gear because fist gear is very very low in the six speed. The 3.08 is something like a 4.10 with the 4 speed.

 

Be happy.

[kalashluvr]

X2!!

 

What about leaving it in 5th for extended periods?

 

(thanks for the advice guys/gals)

[QUIKAG]

When I tow my Vette to track events with my Yukon, I always put it in M mode and lock out 6th gear. It cruises just over 2k rpm with 3.42 at 70mph which is perfect. Of course, I drive 80mph most of the time and it's around 2400rpm. Motor is very happy at this rpm and never needs to kick down.

[kalashluvr]

You have a 3.08 rear gear because fist gear is very very low in the six speed. The 3.08 is something like a 4.10 with the 4 speed.

 

Be happy.

 

Actually very happy with the setup....I'm not sure how much of a difference a 3:42 would be in my commute. It would probably shift the same number of times in my commute. I have to turn my radio down to hear the darn thing run it is so smooth!!

[shocktrp]

If they had replaced the 4-speed column shifter (P-R-N-OD-D-2-1) with a 6-speed version (P-R-N-6-5-4-3-2-1) - then the selector lever would be under the column hitting your leg if you tried to put it in 1st gear.

 

The "M" mode only solves this problem - it doesn't change anything else.

 

5th & 6th are both OD gears - you can't hurt the truck driving in either one of them (you really can't hurt the truck driving in any gear because there is a rev limiter) - but it will hurt your gas mileage.

 

Same thing for the "tow/haul" mode - it hurts your mileage but not the truck.