Great mileage, but feels a bit rough

ha Im gonna jump on what every one else is saying who cares about the skip you are getting the same gas mileage as a honda civic. good heavens man keep the skip!

 

Hey do you mind telling us what month you bought it? Maybe you got one with a transmission that goes straight to 6th gear/neutral after you let go off the gas to increase the MPG.

 

February. Can you fill me in on the tranny comment please? Are there different transmissions?

 

What octane of gas are you using? My '16 taco has about 1000 miles on it and I have not had any issues with it shaking or vibrating. It's been super smooth. I carry a lot of weight in the bed every day due to work. I started off using non ethanol gas and the third tank of gas seems to be getting better mileage. I know the engine needs to break in. But compared to my 2010 trd sport 6 cyl. This engine rocks, so far. I will keep an eye on the mileage, I live in Fl. so no hills, it will be interesting....

 

Regular 89 octane.

 

It's a shame the OP mixed together 2 discussions in one thread. I too have the "skip" or "jerk" or "miss" or "shudder" and it has been reported previously in other threads. I would gladly give up a mile per gallon to get rid of it. For those who say don't worry about it, that's a whole lot easier said than done. Imagine feeling like you're driving a vehicle that needs an old time tune up every time you slowly or moderately accelerate. Maybe a lot of you are too young to remember tuneups but it feels like a spark plug or two is fouled out or the old style points are shot. Obviously it is neither. Mine did it first on the way home from buying it. If I would have felt it on the test drive, I would not have bought it but all the streets we drove on the test drive were very rough and it is hard to tell the sensation from bumps on a rough street.

Anyway, it aggravates me every freaking day to the point where I'm thinking about getting rid of it. I have not yet brought it to the dealership mainly since several other TW posters have tried and have had no luck with a fix. Either the dealers say its normal or say they can't feel it. In my opinion the problem is with the engine, not the transmission. On a smooth quiet road I can hear the engine sound change when it is jerking. It is noticeable most when accelerating through 4th and 5th gears. If you are having this problem, I would appreciate a PM and hopefully we can get an offline discussion going about possible solutions and courses of action. Thank you for taking time to read my rant. I will be bringing mine to the dealership soon, but I have little hope of a fast solution. I guess you can jump me for complaining about something I haven't tried to get fixed if you want to, but I really do not think there is anything Toyota will be able to do for the problem.

 

Every 6 speed auto transmission in the third gen taco's are the same.

If you search this forum for the word transmission, you'll get like 1000 different posts where people complain about their transmissions shifting every 2 seconds.

My curiosity was that maybe you have bought a truck that had an update on the transmission computer that would hold gears longer or shift up to 6th when you let go of the throttle. Makes sense?

I too have a Sport and it was made in Feb. I get like 24-25 MPG on the freeway 21 mixed.
Mine is Long Bed BTW.

 

@Clydeski71

To really tackle your issue. I have three theories.
Theory ONE:
WHAT IF, you had something stuck in your fuel line and wasn't able to deliver enough fuel at low RPMs?
This explains the High MPG and shudder at low RPMS.
It's a long shot but it can be true.

Theory TWO:
WHAT IF, your engine was stuck in Atkinson Cycle mode?
Explains High MPG and shudder at low RPMs.

Theory THREE:
WHAT IF, your engine is only delivering fuel via EFI and not PORT?
I've seen on this forum and fuel that is delivered via EFI is usually in high RPMs.
This kinda explains high MPG but it does explain shudder at low RPMs.

To see if any of these problems are true. You can test drive another Tacoma. If that new Tacoma has higher torque in the low end of the RPMS it can be theory 2 and 3. If you feel more power over all it most likely can be theory 1 and 2.

Whichever. Good luck.
One way you may be able to fix this would be to disconnect the battery to reboot the computer completely and hopefully have a fully functioning engine. Or if my first theory is correct, you can get the fuel line "unstuck" by doing some burnouts off the road.

 

I think your Tacoma might be displaying Imperial gallons rather then US gallons. If thats the case you are getting 23.3 miles per gallon rather then 28.
Check your settings.

 

I can see it being possible.. I can make mine repeatably get 26.X mpg. If i drive it more "normal" I get around 24.5 though.

 

Interesting post from James_Bond....the roughness smooths out as soon as it shifts to a lower gear, so he may be onto something there. I'm not sure about the imperial gallons approach although an interesting thought. I have verified the mpg by going on some longer trips with known distances, refilling the tank and calculating the mpg manually. By taking the # of gallons the gas station pump reads and calculating against total miles driven for that tank, it is close enough to validate the trucks computer for me. For further clarification, i am not feeling what i would call a shudder or anything like that. more like the sensation a skip would produce, but milder than that. again, the best term i can find is it's a little rough. i would suspect the diagnostic computer would register a misfire or something if it were doing that. You guys are way past my understanding of this stuff.

 

How fast are you cruising at? It would be very plausible to get the kind of mileage you are referring to if you were cruising at under 60. The epa does their tests at actual speeds on highways not on flat country roads going below the speed limit. I could see how what you're explaining is possible. I found though in previous vehicles that getting the higher mileage by forcing the vehicle into overdrive is trading penny's for dollars. The overdrive will get destroyed over time doing this because it is not intended to be working so hard

 

yep, most of it is done on roads under 60. it falls considerably on interstates, especially up here where we have a lot of hills the interstates need to pass over. Good Point!!

 

No one is forcing overdrive.. You drive and the transmission automatically goes up to 6th...

For the roughness. I think it is very smooth(relatively) to be going at 1200-1500 rpms.. In all of my previous vehicles, if I put them in that range, it sounds and feels very abusive.this engine goes right along.. Not incredibly smooth but I'm thinking it has to do with the timing associated with the Atkinson cycle.

I'm beginning to really like this combination. Mine has seemed to really calm down with shifting (even in cruise control). In the end..it is a 6speed and you can't take advantage of the high gear count if it doesn't..well..shift...when approaching a hil it shifts to 5th and holds it as long as needed so that it's not hunting..

Every once in a while I will catch it in a wrong gear and it has to change.. But that's from where my throttle input is and the scenario (rolling downhill then immediately uphill, or stop and go). Usually it's me trying to manipulate it with the throttle to shift how i want...if I just drive it with a very basic linear throttle input, it does great..

 

I would suggest against forcing the truck into 6th gear though. 5th and 6th are both overdrive gears. You'll tear up your tranny long term.

 

I believe it.

I got almost 24 MPG in my 4.0 once...flat highway @ about 60 MPH. With another overdrive gear, better aerodynamics, a short bed (slightly less weight), and a more efficient engine than the 4.0 I don't think 27-28 is out of the question in the same scenario.

 

Genuinely curious.. What would "forcing" an AT be?.. I know what you mean in a MT and you feel when it's too low. Also of course, always drop to S4 when pulling or hauling anything substantial in an AT..

I just don't understand the worry with driving in D with normal truck weight and letting the truck shift as needed into overdrive. Are you suggesting if everytime we go through town at 35mph to put it in S5 or S4?

 

Overdrive is intended for cruising speed not for gaining speed. Imagine getting rolling in your manual and then switching to 6th gear trying to save gas. The gears just aren't intended to work that hard at low rpms. What the op described was similar. If you get rolling and feather the gas it will want to upshift especially with the new automatic transmission.

 

I get what your saying but the way this truck downshifts so readily, I don't believe it will put itself in a high load situation under normal driving conditions. Feathering the throttle will just result in it shifting up and then immediately downshifting in my experience with this drivetrain. All this goes out the window if you slam the pedal everytime though.

Totally makes sense when hauling though.

I would dare to say that highway speeds put a larger load than overdrive low speed accelerating. And with him getting 28 mpg, he's not accelerating anywhere fast anyway.. Lol

Just my .02

Thanks for the warning though. Better safe than sorry.