Driving in S-6 fuel mileage.

For the past week or so I've been driving my new truck, 4500 miles on it, in S6 and seem to be getting a little bit better mileage. It still up and down shifts on its own but is this a correct assumption that its helping or could my truck just be getting broke in? It just seemed though that once i started doing this mileage instantly started increasing by about 2 mpg.

 

Yea i had read that engine breaking didnt work in shift mode which is fine even though i like it on some of our hilly Ozark roads and I'll drive it in D when driving through the mountains but on the highway I've been just putting it in S6 as soon as I put it in gear and going on about my way. I kind of like it.

 

So "S" Shift mode is potentially desirable for daily driving where gas mileage is a priority?

Here is a line out of my 2017 manual... seems to go against this theory.

"For best fuel economy during normal driving conditions, always drive with the shift lever in the “D” position."

 

I've got 5500 on my 2016 4x4. I feel the engine is just now getting through the break-in phase. Just did a 180 mile drive yesterday (in D) and got 16.5 mpg. The best so far and a third of that was through stop and go rush hour L.A. traffic.

So your increase might be a little of break-in and shift selection.

 

I just started doing it last week and pretty much on highway driving, I have to think to put it in S6 and don't think I've done it in town but only once or twice.

 

I'm somewhat confused by this post. I tow my camper in S5 with the tow haul engaged. From what I see, the S mode limits the top gear. I can use the S mode to down shift if I need to control my tranny temp on hills or to provide more engine breaking. Are we saying that using the S mode and cruise control, eliminates the engine breaking?

 

Im pretty sure the engine braking is simply the tranny being controlled by ECM logic and down shifting on its own. I notice when I crest a hill at say 40 in D. Then the truck seems like it maintains 40 going down the other side. If I crest at 40 and wait a bit and use brake pedal to slow to 30 the tranny will downshift to assist in the slowdown.
When towing I simply downshift manually for the same effect.

 

I just bought a 2017 Tundra 2 weeks ago. I am the type that reads the owners manual cover to cover.... There is a statement in the owners manual that says engine braking does not happen when the cruise control is engaged.

So after reading QSX15's post that makes sense, if you tap the brakes to slow to 30, the cruise control is no longer engaged until you re-engage it with the switch.

 

Guess the 2010's were different. On mine, it'll stay within 3 mph going down a hill while in Cruise. I'm NEVER in "D" because I'd rather choose the gear I know to be best for load, road condition and speed.

 

you aren't choosing the gear, you are just setting the highest gear it can go into. it will still shift as it pleases.

 

When I move my shifter up or down in 'S' Mode, from one gear to the next, the transmission doesn't "shift as it pleases". Shift to ANY gear, it'll stay in that gear till another one is chosen. This is how my 2010 operates, newer Tundras may be different. I'm surprised the Sequential Shifter hasn't been deleted, seems like very few Tundra owners make the effort the use it.