auto trans - Low speed driving in high gear

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Hello everyone,

I am new here, this is a very informative site and a lot of knowledgeable people here. I found this site when I was researching 0W-20 Synthetic oil but I have another question. I am sure you all are tired of 0W-20 synthetic vs. dino questions! lol

I recently bought an auto 5.7L v8 after driving manual trans cars forever ... when I am going about 30 MPH and not accelerating for example in city driving, the car is in the 5TH gear and about 1000 RPM and then it shifts into 6th gear (highest) at about 40 mph. not sure if the torque converter is locked or not ... the rpm is so low that I can't tell!

I manually shift it back to 3rd gear when going 30 mph to get the rpm at least near or below 2000.
coming from manual trans background the 5th/30mph is kind of a foreign concept!

I am not concerned about fuel consumption otherwise I wouldn't have bought a v8! I wish the car had a 5 front gear manual trans!
not sure what is the best for the engine & transmission in a long run. let it do its thing or take over?

Thank you!
 
Seems to be the "in" thing now. Our new F150's here do that I've noticed. I wouldn't worry about it and let it do its thing.
 
Let it spin on down low. It'll rev and shift if you need it to. I personally enjoy having a large engine that just loafs along at low revs.
 
One of the worst vehicles I've ever driven that does this is my 1990 K1500 Chevy truck.

That truck shifts to OD at 35MPH!!!! So when I drive around town, I always keep the transmission out of OD. Otherwise, it wants to lug all the time.

I guess this is why installing a "shift kit" was so popular in the 80's and early 90's.
 
I'm on the forum for the new Colorado/Canyons and this drives many people crazy, to the point of buying aftermarket reprogramming (tunes).
 
I manually shift my autos all the time. Just adds to the fun of driving for me, plus around town, lower gears help my Cummins warm up and the exhaust brake is more effective.
 
I would let it do its thing on a daily basis, it will not hurt neither the engine nor transmission, despite what others might feel about it.
You have to remember that a fluid coupling allows slippage, unlike a friction type coupling, so you really cannot lug the engine.
 
My Maxima stays in OD with the TC locked a bit bellow 35 MPH at 1100 rpm, and even going uphill - up to a point. It obviously lugs the engine, and even thought I'm not sure how ping sounds like, it must be the noise and vibration this engine makes at 1100 rpm under load.
 
On the Focus in my sig, I have started locking out the 4th gear around town.
From my understanding, lugging the engine and causing it to constantly shift b/t 3 and 4th gears causes harm to the engine and trans. Better to just lock it out until higher speeds are reached.
 
For 3-4 mile trips near home the car never sees over 40 mph and my shift point to OD is at 35-38 mph. These days I just leave it in 3rd for shorter distances. Once up to 45 mph OD is fine. Though to be honest, I have a tough time telling when the TC is locked or unlocked.

I can't see how a transmission hunting all the time from 3rd gear to OD and back (35-42 mph) can be anything but detrimental to it. And keeping it in 3rd for the first few miles (2000 rpm) will speed up the engine oil warmup to the desired 170-180 deg range.
 
Originally Posted By: Phishin
One of the worst vehicles I've ever driven that does this is my 1990 K1500 Chevy truck.

That truck shifts to OD at 35MPH!!!! So when I drive around town, I always keep the transmission out of OD. Otherwise, it wants to lug all the time.


My 89 GMC does the same thing, kind of glad to hear this since I had a rebuild put in 3k ago so I know it's normal.

Do you notice it shifts harder when in D vs OD?
 
I actually like it on my Elantra. Less noise, and no reason to rev when just loafing along. What I dislike is the auto downshift when I let off the gas, especially down a grade. It drops to 5th automatically (hiway) whether it needs to or not. I know they do it for compression braking, but to me, harder on tranny, and brake pads are cheaper.
 
With an auto transmission, put her in Drive and forget about it. If you tow or haul a heavy load, turn off the overdrive.

If the shifting bothers you, and it's available on your model (you don't say what year/make/model it is ... do so next time you ask for help here) try Sport mode.
 
Originally Posted By: Phishin
One of the worst vehicles I've ever driven that does this is my 1990 K1500 Chevy truck.

That truck shifts to OD at 35MPH!!!! So when I drive around town, I always keep the transmission out of OD. Otherwise, it wants to lug all the time.

I guess this is why installing a "shift kit" was so popular in the 80's and early 90's.


I find my 02 Silverado to go into OD around 30mph then lock up at 35mph. If I keep on the gas while approaching a hill it won't unlock until it gets below 30mph. Lugging an automatic around 1,000RPM's is a sight to see.
 
This is from the owners manual of my old 6 spd 1997 SS Camaro.

bear in mind 6th gear on 4th gens was a .50 overdrive
70mph in 6th was around 1500rpm if memory serves and I think skip shift kept you around 1000-1100 rpm. That "feature" used to really let you know the transmission mounts were working thats for sure.

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Originally Posted By: brave sir robin
This is from the owners manual of my old 6 spd 1997 SS Camaro ...


you would think Camaros are made for acceleration & speed ...
wouldn't "skip shift" slow down the acceleration if you needed it? sounds like you can over-ride the skip shift and start in 2nd gear for acceleration! you don't need the first gear anyways. lol weren't the old Camaros 3 speed?
 
Originally Posted By: Kibitoshin
I find my 02 Silverado to go into OD around 30mph then lock up at 35mph. If I keep on the gas while approaching a hill it won't unlock until it gets below 30mph. Lugging an automatic around 1,000RPM's is a sight to see.


based on what I am reading, I am assuming that lugging is not bad if TC is NOT locked. is that correct?

what if you are driving above 30 mph and below 35 mph and in OD & locked as you described it.
Is lugging bad under locked condition?
 
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