Slipping the car into I is wonderful for slowing down on icy roads and hills. Once you get used to the down shift points it becomes very predictable and more gentle than braking and locking up. And yes, it is very fun in the good weather as well and allows for some good mid range rpm acceleration.

 

Something was out of the norm, but it wasn't the transmission.

It turned out to be a bad hub/bearing on the passenger side. They replaced the hub last October and the noise went away.

 

The old overdrive tranny's that GM used we were told to drive in (3) so we did not tear the overdrive up. So I will try the (I) gear today

 

Another great post full of good info.

I had never thought of driving in any gear other than drive. I am going to give the "I" a try on my next time out.

 

I love it ! I live in an area with big hills and just to get into my garage I have a 6% grade. It allows me to save on the brakes while everyone else is riding theirs and get up and down these hills without gears slipping.
The best part is freeway cruising, someone will want to play games and I just shift and leave them sitting :) works for me

curtsy
Elle'

 

Sounds to me like some frustrated drivers trying to justifying their automatic transmission purchases. (Which I also have) Yes the “I” (intermediate)position is fine for some deceleration but it has a major flaw.

I travel this hill on my daily commute and “I” might work good for you but it absolutely SUCKS for me, actually it terrified me the first time I used it to retard (hold back) when it up-shifted by itself with the resulting acceleration in the middle of the corner! I thought something had broken. What possible good is a transmission that up-shifts by itself when it is being used to slow momentum. Save on brakes, I don’t think so!

My PT Cruiser turbo with the auto-stick was excellent engineering (and fun), …..But anyone that would design an transmission that up-shifts from a supposedly hold back position when it feels like it is deranged.

My SS will have a 5 speed, the automatic is unsafe.

 

When it hits 4,000 rpm it will shift...that's just the way it's programmed.

 

Maybe I'm missing something, but I used mine for the first time tonight and I believe this gear is simply the old Drive 2 in most cars - ie: L, D2, D. or to put it another way, 1st, 2nd and 3rd. The "I" by-passes 3rd gear and you never hit overdrive. It seems to me you will rev higher, work the tranny more, use more gas and go slower. I also think it may by-pass 1st gear as well.

The old theory of using 2nd (or in this case "I") was for starting out on slippery roads so you wouldn't spin the tires.

I realize this is an old thread, and I haven't gone back thru the earlier posts, so perhaps someone already came to this conclusion.

 

I thought I'd play with this today too and was unable to duplicate Ray's fright going downhil. I couldn't get it shift up in I position when my foot was off the gas in 2nd or 3rd. It's certainly is a heck of a lot noiser. I felt like a fart can guy slowing down as I couldn't tickle it into 3rd and less revs and slow that way. You do more coasting in D but I sure wasn't on the brakes as much in I and I'm wondering if you're not lugging the engine as much starting in I.

 

At the crest (top) of the hill (maybe 50 mph) I shift into what I would presume to be seconded gear (“I”) as I have been doing for 30 years on this hill with various vehicles and as the rpm increases and with a little brake just entering the bottom corner it will up-shift. It is unnerving to say the least and defeats the purpose of saving the brakes. As Black Rose mentioned you have to get over 4000 rpm and I am going maybe 40-45 mph on a long hill.

The owners’ manual really sucks on this; we need some tech help here!