10-speed automatic truth (Ford and GM), from Next Gen Drivetrain

[Rob Hall]

Yes, fuel economy and efficiency.  I’ve seen almost 30mpg highway in my Cadillac with the 10 spd auto and 3.6 v6…not bad for a 4100lb AWD luxury sedan.  

[TECHMAN]

2 hours ago, 1972coronet said:

Where is this fantasy land in which fuels that cost less than $5 / gallon ?

Columbia, Kentucky (south central Kentucky)  paid $2.64 gallon this morning....   

DJ

[1972coronet]

23 minutes ago, TECHMAN said:

Columbia, Kentucky (south central Kentucky)  paid $2.64 gallon this morning....   

DJ

My word ! Gas - let alone diesel - hasn't been that cheap in at least 20 years (maybe more).

Now, I will bow in deference , in respect to my railroading the original topic. 

[Ace-Garageguy]

15 hours ago, Rob Hall said:

Yes, fuel economy and efficiency.  I’ve seen almost 30mpg highway in my Cadillac with the 10 spd auto and 3.6 v6…not bad for a 4100lb AWD luxury sedan.  

Once you're on the highway and the torque-converter is locked up in top gear, the ten-speed silliness has absolutely NOTHING to do with mileage.

It's only contributing to increased mileage around town, where it is intended to keep the engine in the most efficient rpm band during constant off and on acceleration.

Edited 18 hours ago by Ace-Garageguy

[Ace-Garageguy]

23 minutes ago, 1972coronet said:

My word ! Gas - let alone diesel - hasn't been that cheap in at least 20 years (maybe more).

Now, I will bow in deference , in respect to my railroading the original topic. 

Averaging around $2.85 in the Atlanta suburbs.

[TECHMAN]

1 hour ago, Ace-Garageguy said:

Averaging around $2.85 in the Atlanta suburbs.

Yep, but when we moved up here (from east Texas) in June 2021, gas was $1.49 a gallon, so I don't exactly consider "almost $3 a gallon" that much of a bargain......  By comparison to the $5 a gallon we were paying in the early 2000's, THEN it's a bargain....😉   Seems like that's the way they've slid all the price hikes past us, go up 100%, then drop 50%, and all of a sudden, "WOW, WE'RE GETTING A BARGAIN!!!!  And  our "45speed transmissions" will get us so much gas mileage, we'll probably have to drain the tank every other day!!!!!!    😄

DJ

[peteski]

3 hours ago, Ace-Garageguy said:

It's only contributing to increased mileage around town, where it is intended to keep the engine in the most efficient rpm band during constant off and on acceleration.

Yeah, when I'm driving gingerly on a level road or down hill, my 6-speed Kia is already in 4th gear at around 25MPH!

Edited yesterday at 02:32 AM by peteski

[stavanzer]

John Shoe, it's $3.89 to $4.09 in Bakersfield, 2 hours north of you.

[1972coronet]

8 hours ago, stavanzer said:

John Shoe, it's $3.89 to $4.09 in Bakersfield, 2 hours north of you.

That does it ! I'm filling up in Bakersfield every time now ( or at least on my way to that $15 Prime Rib in 'Vegas ). 

Seriously though, how can it be less expansive in Kern County ? 

[stavanzer]

I don't know.

I do know that our gas stations get their gas from Refineries in Benecia, and Long Beach.

[TECHMAN]

15 hours ago, Ace-Garageguy said:

Once you're on the highway and the torque-converter is locked up in top gear, the ten-speed silliness has absolutely NOTHING to do with mileage.

 

Have noticed, in the wife's little Toyota RAV4 (6 speed auto trans), going down the Cumberland Parkway, in level spots, tach is about 2000 running 70, but there are few level areas, moment you head up one of the 2-mile long 6% grades, first convertor kicks out tach up to 2600 (approx.), then a ways farther, down-shifts and tach jumps up to about 3400.....  Watching the "gas mileage readout", gas mileage drops proportionately to the tach climbing upwards......  Don't think that a dozen more gears is gonna do any great thing in these hills.....  In defense of the "multi-gear" transmissions, having additional gears to work with, you are keeping in the powerband, and not "over-working" the smaller engine to climb the hills.....  

DJ

[Ace-Garageguy]

1 hour ago, TECHMAN said:

Have noticed, in the wife's little Toyota RAV4 (6 speed auto trans), going down the Cumberland Parkway, in level spots, tach is about 2000 running 70, but there are few level areas, moment you head up one of the 2-mile long 6% grades, first convertor kicks out tach up to 2600 (approx.), then a ways farther, down-shifts and tach jumps up to about 3400.....  Watching the "gas mileage readout", gas mileage drops proportionately to the tach climbing upwards......  Don't think that a dozen more gears is gonna do any great thing in these hills.....  In defense of the "multi-gear" transmissions, having additional gears to work with, you are keeping in the powerband, and not "over-working" the smaller engine to climb the hills.....  

DJ

My older Silverado with a 4L60 does exactly the same thing on a long grade, as does my Jag XJ-6 that I swapped a 700R4 into. For that matter, so does the little 2-liter Neon and the '96 Blazer.

First the lockup converter kicks out, then if that's not enough, they shift down a gear.

Having 6 more speeds would accomplish zip, zero, nada, nothing in this situation.

The superior highway fuel mileage Rob Hall claims for his Caddy has everything to do with improved combustion chamber and porting designs, and more accurate engine management achieved over a couple of decades.

 

Edited 15 hours ago by Ace-Garageguy

[oldcarfan]

On 9/14/2025 at 2:26 PM, 1972coronet said:

Where is this fantasy land in which fuels that cost less than $5 / gallon ?

Here in central Texas we've been lucky this summer. Gas is currently around $2.47 per gallon and the most it's been is $2.79 whenever a new 'crisis' hits. 

[NOBLNG]

We are paying around $1.33cdn/litre here. If my calculations are correct that is about $3.68usd/us gal.

Edited 8 hours ago by NOBLNG