Per the user manual when towing ECT should be in Power and the transmission set to S4 (for the 6 speed).
I run >3k rpms cruising at 60mph and get 8-9 mpg.
What am I doing wrong? 4.1 mpgs! (1 Viewer)
- Thread starter ColoradoSequoia
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I run >3k rpms cruising at 60mph and get 8-9 mpg.
bloc
SILVER Star
Plus higher RPMs keep the oil pressure up and fan spinning away.
Drive right behind a semi to save mpg. Just radio the driver you’re hitching a ride in case he brake checks you.
Ha! This does work in RL! "hey pal, I'm the jerk behind you. thanks for the ride."
Yes, can work very well for almost another 1MPG, or about 10% more range and 10% less cost, when you're getting 10 MPG. In CA, it's hard to find a rig that I want to follow trailering vehicles are limited to 55MPH which commercial operators will tend to follow. I'll find the odd one doing 65 MPH and fall in behind. It's can also be more relaxing as people getting up behind you won't get up as much on your ying yang as we're just falling in line.
When you say set the transmission to S4 is that only for the 6 speed vs the 8 speed?
Another thought is check trailer bearings and brakes make sure they are not running hot.
So you have me curious and I went and looked at my 2016 owners manual and no where in my manual can I find ECT is for towing.
I also went through the towing section.
Under vehicle transmission controls shows a picture of the ECT PWR switch and says:
Power mode
For powerful acceleration and driving in mountainous regions.
Press the button again to cancel power mode.
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Yes, S4 is for the 6 speed (I have a 2013). From what I’ve seen on here the 8 speed it is S6.
I’m also to understand S4 and S6 are the highest shift points where the torque converter is locked
The TC will lock in 5th or 6th, but when you're towing with a decent size trailer it'll regularly unlock to attempt to give you a little more power before it then downshifts. So you spend a lot more time with the TC unlocked in 5th or 6th, which generates more heat.
In theory you can run in any gear so long as the TC stays locked. If you run in 4th that's a 1:1 ratio gear so it tends to stay locked. With a lighter trailer you might get away with 5th.
(note on the 8 speed add 2 gears to whatever I just said above. Also on the 8 speed it can lock in 5th, which is >1:1, though again S6 would be the recommended gear)
wiseinvestor
GOLD Star
Last weekend I set a burger king bag with lunch for 5 in front of the shifter for a min. I had the wife searching through the manual for miles looking for what the ECT PWR light was for. I have had to look it up 3 times in the last couple years because I always forget about it.
- Thread starter
- #29
60-75 probably faster than I should be.
Is that actually 75 MPH, or the speedo reading 75?
Maybe try backing off ~5-10 mph for a stretch and see if it improves. I generally find I gain 1 MPG per 10 MPH.
Also if you haven't tried it yet I still suggest trying a few tanks of premium. Or if you have an OBD reader watch the knock correction/ignition timing advance and A/F mixture and see if the truck is dumping fuel into the engine to cool it and backing off the ignition timing. Definitely when I've had a tank of s***e gas (low octane or old or something) and my MPG drops to ~6 I can see the ignition advance drop off. It usually takes 2-3 tanks before the ECU recalibrates and puts the timing back where it should be. (In fairness when this happens I also find it's a struggle to maintain >65 mph in 4th gear, even on flat lands).
Maybe try backing off ~5-10 mph for a stretch and see if it improves. I generally find I gain 1 MPG per 10 MPH.
Also if you haven't tried it yet I still suggest trying a few tanks of premium. Or if you have an OBD reader watch the knock correction/ignition timing advance and A/F mixture and see if the truck is dumping fuel into the engine to cool it and backing off the ignition timing. Definitely when I've had a tank of s***e gas (low octane or old or something) and my MPG drops to ~6 I can see the ignition advance drop off. It usually takes 2-3 tanks before the ECU recalibrates and puts the timing back where it should be. (In fairness when this happens I also find it's a struggle to maintain >65 mph in 4th gear, even on flat lands).
You’re right, neither one of my manuals says anything about towing in S 4 or 6 or to use ECT. This has become accepted as fact because so many members do it but the only thing in my manuals says is to slow down when going downhill you should downshift. Having said that, I have found that the truck does drive better when on cruise control in ECT turned on because it needs less “help” from the gas pedal on uphills.
It isn’t in my manual either but I have seen a screen shot/file in a thread somewhere on MUD?
LOL
I noticed the ECT was on the other day when I filled up and my average fuel mile had dropped 2.x - 3.x mpg. Seems my daughter's puppy walked on the ECT button and turned it on.
Does "S6" lock the torque converter or does it just max out on the 6th gear? I have never used the feature before.
I have seen threads on the Australian forums purchasing torque converter lock up kits for towing.
afgman786
SILVER Star
S6 maxes your gear selection out is all that does. That fact that 6th is your 1:1 gear your torque converter should stay locked longer where in 7 and 8 it'll unlock more easily.
Also the Australians run the torque converter lock up kit on diesels, I can see the benefits of having that state side especially for wheeling and in a downhill situation.
I use ECT all the time and I've seen zero difference in mileage, at least on my 2013. *Maybe* 0.2 or 0.3 mpg when all is said and done. Before mods I used to get 17+ on the highway, regardless of the setting. All ECT PWR does is change the shift points so the transmission holds your gears longer. If you're light on the throttle you'll notice that ECT is really where the shift points *should* be, and the ECO setting makes the shift points happen too early, like you're driving a Corolla. If you're very heavy on the throttle then there's literally no difference because the transmission will hold the shift point longer anyway.
I'm sure there's a way in which you'd burn more fuel using ECT PWR because you're always in a lower gear, probably some suburban route where you are continually going from a stop to 40-50mph and back and you're heavy enough into the throttle that the transmission waits to shift, but not so heavy that the transmission would've held the gear regardless. If you're seeing 2-3mpg difference on part of one tank of gas, I suspect something else was at play.
- Thread starter
- #36
That's actual MPH.
Update on MPGs on this trip:
- Flagstaff to Grand Canyon: 7.9
- Grand Canyon to Vegas was around 8.5 mpgs (while staying under 70 mph). While the net elevation gain is negative, it's a very up and down route.
From Vegas to Moab I'm going to limit my speed (and RPM) a bit more and see how that works. This route will have positive elevation gain so we'll see.
I'm pretty convinced HIGH SPEED/RPM (around 70-75 mph) and HIGH WINDS is what killed MPGs from Denver to Flagstaff...
I've found cross-winds tend to be worse on mpg than headwinds for some reason, towing or not.
I've never seen below 6 mpg (actual), even with winds at 70mph. 4.1 definitely seems like an outlier (I'd hope)
I've found the perceived effects of ECT vs non-ECT will depend on mods and use. With upsized tires that effect gearing, particularly 33" and taller tires, ECT will really help to dial back in the shift points. Otherwise to your point, it will feel like it shifts corolla early. With taller tires that already effect efficiency enough, it may seem to be no impact on MPG. I've found that ECT will use a bit more gas, which has been true on both my 100-series and 200-series, as it uses a more aggressive shift map holding gears. Just about short of 1MPG difference in use without towing.
Now that I'm on 35s, re-geared to practically stock gearing, shifts don't feel short and are spot on, without any Corolla feel. ECT holds onto gears a tad longer than needed, as it was designed. I exclusively use ECT when when towing as it also makes throttle tip-in more aggressive, so can't say if it impacts much there. Probably not much to your point as that's not the significant variable in that use case.
Exactly my experience as well. Though I have more gear, so ECT has more neck snap in it than I want for toodling around town. The kind of fun that has tickets all over it . . .
I used to go back and forth with ECT PWR on and off when I first bought my truck and it was stock, except for the roof rack. (I would use it, my wife would turn it off, and so sometimes I'd neglect to notice and remember to turn it back on). I never saw a difference in mileage. I realize changing shift points should create a difference, but I never saw it. Back then I'd get 17 MPG on the highway all day, and about 10-11 in pure city IIRC.
With taller tires and stock gears, my wife leaves it on all the time now as the shift points on non-stock tires are lethargic. I'm pretty sure when I get the truck back with 4.88s (tomorrow, hopefully) like you and @grinchy I'll end up running in ECO mode again except when towing. Because I'll have shorter gears I'm very curious how MPG will be affected and will be testing with it on and off again...
