2GR-FKS more 'Atkinson' than Prius.

“What we’re doing is we have a slit on the side of our injector and we’re blowing that carbon off,” Mike Sweers, the ’16 Tacoma’s chief engineer, tells WardsAuto here during the truck’s media preview. “If we tried to use just high pressure, using just the nozzle itself, you would clean the bottom of that nozzle.

“But since the carbon grows from the outside and comes around, you would still plug up that injector,” he adds. “So by cleaning on the outside of that, we get a clean injector all the time.”

Makes sense to me, the slits open and break off deposits before they have a chance to surround the tip of the injector. A cone is a very strong shape for adherence, a partial cone, not so much. Break it off before it gets strong.

 

You need X amount of fuel for X amount of air. How much fuel is injected is split into a percentage done by the port injectors and the rest done by the direct injectors.

The cleaning that needs to be done is removing carbon from the intake tract, specifically on the intake valves, outside of the combustion chamber. So the cleaning occurs whenever the port injectors are functioning. If the port injectors are injecting any amount of fuel, the direct injectors will simply be injecting less fuel.

I wouldn't expect any significant change in fuel economy during this operation, except for a minor amount of extra due to cooling losses from not direct-injecting the fuel meaning you couldn't run the engine quite as lean, but the direct injectors are never fully off, so I would think the cooling effect would still be present, even if it is to a slightly lesser degree.

Jeff

 

Great analysis, Geoff.

Real question though, will it make more power than vtec?

 

There is a lot of wasted additional technology and research including the motor and the transmission and air resistance work if all you get is an additional 2 mpg. I half expected 25 mpg highway at least. I really don't need to hear "real life results may be different" as real life results always are depending unpon the driver. These are tightly controlled measures that you would think, might Give you a greater difference of mileage of the 2016 vs 2015 Tacoma. We listened for months about all the newness of this truck and just assumed.....at least I did, it would perform more economically. Guess I did the right thing buying a 2015 for probably $8000 plus less

 

Dagosa - the EPA is a test protocol. Not every driving scenario is covered by the EPA protocol. It is like when you studied for a test in school and a question you studied wasn't on the exam. It doesn't mean that knowledge is useless. It just wasn't on that specific exam. Again, wait until some real world number and Consumer Roports runs it. That will give us more data.

 

Ha, if you didn't have 600+ posts I'd call you "NOOB" and wonder if this was your first day on the Internets in all screaming caps ... but I am with you wishing that were the case!

 

I understand the valve cleaning but I would think no need for any cycle to do that, since port injectors have to fire at some time, and clean top of the valves. The quote from Toyota Chief Eng talks specifically about additional cycle to clean Direct Injectors.
Thats the part I am curious about. I am guessing FSM has to have some good explanation how that works and if needs extra fuel consumed for this to work.
Also curious why Toyota had put this cleaning cycle. Have they see injectors getting carbon buildup?

 

With all due respect, you sound like a good company man. As I have stayed before, I know it's not the actual mileage you can expect, but neither is Consumer reports. None of the test will give you actual mileage but will only represent their driven mileage during their tests. EPA mileage has a strict protocol that does not give driven mileage either, but it eliminates driver variance. So introducing a driver, creates not eliminates and invalid comparison. Though it will not represent the actual mileage, it is specifically designed to use for comparison. In that light, the results of the efforts to increase economy by Toyota according to these tests, is poor. Most owners of the 2 nd gen agree along with Consumer Reports that EPA ratings are close and worth comparison with other cars. The consumer report numbers are all over the place from one make to another. If you think you will drive like the testers at CR....sure use them. My statements are reasonable and I remain skeptical of Toyota's efforts.

When consumer reports numbers come out, Toyota fanboy's will extoll their Truthfulness if they are good and blast CR as bias and unknowing if they are bad.....just like we have with the Tacoma for many years before.

 

I'm saying you take all the data: EPA, CR, fully, comparison tests like pickuptrucks.com. Once all that is out there, you'll have a pretty good idea if the tech works or not. The fact that Toyota went to the trouble of adding this tech and it doesn't obviously manifest in the EPA test tells me that it probably works. People love bragging that they beat the EPA mileage. Think about it as pleasantly surprising their customers when so many people are buying vehicles that promise the moon and can't deliver.

CR is what it is. I find them pretty spot on and while I loved my 4Runner, which is low rated by CR, I didn't recommend it to people that weren't specifically looking for what the 4Runner offers.

 

Each year a new model comes out, it is evaluated according to the EPA protocol in existence at that time. Unless the protocol changes, I have yet to see any models change their EPA ratings from one year to the next. All the numbers from the same manufacturer do not change. That is why I only compared toyota to toyota.....Auto publications generally agree on this...and I paraphrase. EPA ratings are NOT the expected mileage you will get. So you telling me to wait till "real world mileage " comes out from other publications, means nothing. These publications all go on to say (including CR) that EPA ratings are still a very good way of comparing cars, especially those from the same manufacturer who conducted these tests and submitted the results to the EPA. So, I compare 2016 to 2015 Tacoma to 2015 4Runner. K

I am whole justified in saying, there is so little difference in the EPA ratings which are a valid way of comparing models from the same manufacturer.......that the results just doesn't justify the hype. Unless there is an official change in the EPA ratings at a later date, the 2016 Tacoma is little better (1mpg)then a4runner which is heavier, and made with an inferior motor and transmission and has had a valid comparison to the Taco for over ten years.

 

Being no car expert, I read this forum carefully and value the input from you folks. I will say this though, I'll never trust Consumer Reports for anything. On a few things I actually had some knowledge about, they were off so far it was comical and sounded like soundbites from a marketing class. I'd much rather trust the EPA info and your opinions. Forums are the way to go if you can ignore the silliness and trolls.

 

I agree that CR has it's limitations because they can't be all things to everyone. The Tacoma is a case in point. What they think is good in a car can be bad in a truck. Tacos are ment for it's base not to make CR happy.
BUT......I never buy a new car without consulting them. They are a valuable reference....but not a definitive one.

 

I don't like CR much either for general opinions, but they splice a sensor into a vehicle's fuel line to better calculate mileage. That sounds like potentially valid data to me.

Also Mototrend slaps a complicated exhaust/sensor system on its cars to get their real world mpg.

 

I hadn't read about any specific DI injector cleaning, but I will take a look when I have a minute.

Jeff

 

The only Atkinson I know of is the diet.

 

Seatbelt Mike was talking about a cleaning cycle but he never said it would dump extra gas. He was talking about a hot idle cleaning the injectors.

 

If the EPA ratings are so flawless, why is there such wide variation in what hybrids or diesels can do depending on your driving cycles? This Atkinson cycle capability is squarely in that camp. Some will see it as hype (those that drive a cycle similar to the EPA cycles). Those that drive a lot of city or a lot of highway might see a huge improvement. The EPA test cycle is designed to be somewhere in the middle of the bell curve. The CR city and CR hwy numbers are more of book ends to the bell curve. That's why I want to see the rest before I judge.

 

And those who drive the 2015 Tacoma and 2015 4 Runner exactly the same way, will see that big 2 and 1 mpg difference in mpgs. I can get as high as 24 plus mpg under certain conditions with my 2015. I suspect the 2016 will gat 26 mpg under those same conditions...BFD.

 

Yup people dont understand this...
If they were not getting 21 MPG on Old Tacoma they will not be getting 23 MPG on new one either.
Their driving habits are outside of EPA test so they will never achieve those numbers.
Me I dont think I had ever owned a vehicle that I did not hit EPA ratings, and with most, I do better than EPA tests.

 

I am confused what your argument is. Are you saying you don't care about even a (speculative) 10% improvement in mpg? Or that such a difference doesn't matter to you since you already drive a 2015?