Design Approaches for Max Efficiency-- Who is Winning?

Originally Posted by oil_film_movies


Goal: Measure powertrain efficiency to see what progress is being made, and which approach is best.

Formula: (hp/170) x (MPG/28) x (weight/3274)
...It adjusts for weight & power differences, normalized on the Equinox 1.5T numbers.


Using Highway mileage:
2016 Grand Cherokee SRT: (475/170) x (19/28) x (5291/3274): 3.06
2018 RAM 1500 3.0 Diesel: (240/170) x (27/28) x (5624/3274): 2.34

Using mixed mileage:
2016 Grand Cherokee SRT: (475/170) x (15/28) x (5291/3274): 2.42
2018 RAM 1500 3.0 Diesel: (240/170) x (22/28) x (5624/3274): 1.91
 
Tiguan, VW's 2.0T boxy small CUV (only the 2.0T is offered, no choice)... 8-speed automatic gets a lotta credit here:
(184/170)(24/28)(3777/3274)=1.1
 
Good luck finding a base model Forester for $22K.
ATM, the Premium Package car that we bought in July 2017 is about as cheap as a Forester gets and was more like $26K at the best deal I could negotiate. Dealers don't need to give up a whole lot on a supply-limited Japan built model that's in demand.
The base would be a bit of a unicorn. There never have been many out there.
 
My 2 Series averages 26 mpg in mixed driving and 31 mpg with the cruise control set on 80 mph; considering the performance I could not be more pleased.
 
Originally Posted by PeterPolyol
Originally Posted by PandaBear

Mazda has no huge investment, so they "tune" an existing design and throw in more expensive parts, instead of high fixed cost R&D (before HCCI is ready).


Seems a pretty unfair characterization of Mazda who have developed a new engine for each generation of vehicle since the 70's with among the least carryover engine series of any automaker, despite many of the older engines remaining in production (there was nothing wrong with them). And honestly, not one of them could be considerded bad. Many of them were ahead of the curve, like the K-series V6, and Skyactivs. If you go a step further and apply 'new engine releases' to a ratio of R&D-to-revenue, I'd bet they have almost anyone beat in that regard.

An example, they could have kept the older F-series engines going (1.8L-2.2L equivalent to Toyota S-series), but instead had to "improve" weight and friction and shrink packaging, so they created the FS/FP engines, for just 1991-2001 years, after which they began using the MZR which they also designed. Conversly, Toyota had been using the S-series engine since January 1980, and "tuned" and fiddled with it until 2002. And it was a headgasket eating sludge monster that needed special attention, right to the bitter end. Facts.

I have a HUGE amount of respect for the Mazda engineers (which seem loyal to the company and vice-versa), and know intimately how underrated their hardware is. Plus also have to give a serious nod to their total lack of reliance (if not outright ineptitude) on PR and marketing- I don't know anyone that does it worse. They don't seem to spend very much on marketing and it certainly shows


Maybe I should have phrase it differently.

The whole point of Skyactiv is that they do not have to invest in things like hybrid or EV, CVT, etc. The original Skyactiv is basically a tuner car, modified from the factory to run more efficiently (at higher components cost than a "new platform" like CVT or hybrid would have cost. Their auto transmission with multi-disk lockup clutch and torque converter is also to reduce / avoid the R&D cost of going CVT / hybrid. To be fair, that's the low risk low R&D budget way to get the result for their company size. It would not work as well for Toyota as they would have more volume, and the investment would pay off better in a higher investment cost / lower part cost approach.

I too have a lot of respect for Mazda, but the point I was trying to make is, the investment approach is not one size fits all.
 
Originally Posted by PandaBear


The whole point of Skyactiv is that they do not have to invest in things like hybrid or EV, CVT, etc.


Where did you get that from? The Mazda3 Hybrid is one reason why Akio Toyoda persued business ties, other reason to acquire rights to IP for the new A-series engines. Mazda 2 CVT was okay I guess, but that was an experiment. The company doesn't like them apparently.
It's really not cheaper to develop entirely new engines or transmission (or chassis) just because of the fuel or power-transmission method used; it's still billions of dollars, Sumitomo bank wrote the cheques to fund it. The one guy Robert Davis from MNAO had misinfomed the press for a while that Mazda was not interested in hybrids and electric vehicles. That's obviously BS. He clearly misinterpreted the commitment to maxing out ICE development as an aversion to electrification, even though the Skyactiv Hybrid Mazda3 already existed. I say thank goodness they didn't jump off ICE with the others, or else when would we see yet another big jump in full-range ICE engines? Gotta max out the prime mover's potential first, it only makes sense. Apart from all brand new hardware, the logic control is very development heavy and to bring novel implementations to market that arent still obviously in beta, and have them wind up being among the trouble-free hardware on the market is quite the feat. These are things that are happening and there's no way around doing the hard work, you can't fake stuff like that. Remember when everyone was saying the Skyactiv engines with such high compression on regular gas would be knocking all day and blowing up? A tuner engine definitely would though
wink.gif
Conventional thinking is outta here in the new age of motoring
 
About the Mazda strategy, they are just now getting a hybrid to market, after Toyota has done it for 19 years, and Ford for 13 years. ... Mazda seems late to the party. ... Of course their Skyactiv tech has served them well until now. For 2019, their first hybrid will hit the market in the U.S. ... You could say their timing is good. Its probably time they did it.
They built a hybrid in Japan as a concept, and I don't know if it ever was sold in Japan-only. That served as a test & practice for a few years, to make sure they got it down.
 
Last edited:
Originally Posted by oil_film_movies
About the Mazda strategy, they are just now getting a hybrid to market, after Toyota has done it for 19 years, and Ford for 13 years. ... Mazda seems late to the party. ... Of course their Skyactiv tech has served them well until now. For 2019, their first hybrid will hit the market. You could say their timing is good. Its probably time they did it.

Skyactiv X will be extremely hi tech compared to their Skyactiv G engines.
 
Yeah the Mazda3 Hybrid was their first one, leased out in Japan. That upcoming EV was recently pushed back to 2020, engineering is super busy buttoning up the X, but it'll be full EV with rotary range extender option and built in Alabama.

Also related trivia from Japanese sources, the next 6 will be all-new (again), RWD with an inline 6 cylinder turbodiesel available, with subsequent C/D models all going longitudinal RWD/AWD afterwards. As far as post-X ICE, there are rumors that Skyactiv 3 will blur the lines between gasoline/diesel combustion even more, and be able to run on both or similar liquid hydrocaron mixture. Either way, they say by 2030 all vehicles will be electrified in some way. Whatever I just want to see an RX-7,8,9 in the next 5 years!
 
PeterPolyol, wow, that is good Mazda planning there. I do think it was a good move to perfect their hybrid tech in Japan (leases, small numbers) first to get the bugs out. Gotta do that these days for quality.
I did hear recently about the rotary engine range extender engine which reminds me of the current BMW i3 range extended EV model, yet having a smooth running, cool new rotary back there is much better than BMW's buzzy small engine.
[ Off topic, but now I wish Mazda would put that new small rotary engine on a new motorcycle, maybe collaborating with Kawasaki or other company in Japan for it. ]

Interesting how its all shaping up. One thing I learned from this is that my '18 Equinox is fuel efficient because they figured out how to get more mass out, not because their small engine turbos and transmission pairs are all that efficient.
 
One other note on Mazda's electrification of their powertrains (hybrids, future EVs): Toyota has a 5% ownership stake in Mazda now, and is planning to build a joint plant n Huntsville, AL to produce both Corollas and a Mazda crossover there. Therefore, Mazda could just cut a deal with Toyota for electrification since Toyota is great at hybrid tech and already a partner with them.
8 years ago, for example, Ford hired Magna to supply major electrics for the Ford Focus BEV.
 
Yep the joint venture capital tie ups are only deepening. The companies have set up an EV venture called "EV Common Architecture Spirit Co.,". Participants will be Toyota, Mazda, Denso, Subaru and Suzuki. Daihatsu and Hino are also implicated as well as a Japanese battery supplier.

One would think that Toyota has the EV expertise because of their HSD hybrids, but thats surprisingly not the case. HSD hybrids are not at all like EV's in practice. Akio intends to fast track EV development by collaborating with the others in which they intend to basically build a huge common partsbin. Seems to be similar to other EV JVs like Ford and VW. The agreement allows each company total design freedom to implement their EVs as they see fit, but they all save on component development and supply scales.

EV Common Architecture Spirit Co., will apparently have about 18 engineers total, some from each company, dedicated to the EV project. The Alabama plant is supposed to build the Mazda EVs, possibly a Toyota EV along side and Toyota Corollas like you said.

Ford. Ford screwed the pooch for too long. Their whole DoE "bailout grant" with an interest rate lower than the rate of inflation, was 'lent' to Ford under the pretense of developing EV tech. Instead they used it all to fund operations and (gasoline car) plant upgrades. Ford should have been much farther ahead right now with EVs, than some imited production run Eco-halo cars.

It's crazy how companies are flocculating into groups, just to beat the other groups
 
https://www.japantimes.co.jp/news/2...e-get-boost-suzuki-subaru-daihatsu-hino/
https://automotivemanufacturingsolutions.com/focus/bigger-bet-bevs
Quote

All told, Toyota expects its BEV plans to require ¥1.5 trillion ($13.8 billion) of investment by 2030, with about half of the total earmarked for battery R&D. However, Terashi thinks this R&D budget alone is not sufficient. "If you don't have enough capable people, they can't spend money wisely," he warned. Tapping into the shared expertise of partners like Mazda and Denso is obviously helpful when it comes to batteries, and Toyota has also turned to long-standing partner Panasonic, which happens to provide cells to Tesla.
 
Originally Posted by PeterPolyol
One would think that Toyota has the EV expertise because of their HSD hybrids, but thats surprisingly not the case. HSD hybrids are not at all like EV's in practice. Akio intends to fast track EV development by collaborating with the others in which they intend to basically build a huge common partsbin. Seems to be similar to other EV JVs like Ford and VW. The agreement allows each company total design freedom to implement their EVs as they see fit, but they all save on component development and supply scales.
Using the old planetary gearset 2-motor setup like in a CMax and Prius, one could envision scaling down the IC engine (2.0L in CMax) to 1.0L, and scaling up the battery to 20kWH+ or so. Although the Honda architecture is more modular to create a pure EV Accord or Civic. ...Honda Accord Hybrid's non-planetary-gearset setup is practically already an EV, sans the big battery for now, given the electric drive motor in it already makes 181 hp by itself, much of the time using the engine to supply electrons instead of a big expensive battery pack sending the juice.

Originally Posted by PeterPolyol
Ford. Ford screwed the pooch for too long. Their whole DoE "bailout grant" with an interest rate lower than the rate of inflation, was 'lent' to Ford under the pretense of developing EV tech. Instead they used it all to fund operations and (gasoline car) plant upgrades. Ford should have been much farther ahead right now with EVs, than some imited production run Eco-halo cars.
I don't know if Ford saw the current low gasoline prices coming way back in 2008, but in retrospect, Ford made the right decision on trying to avoid throwing too much development dollars at a money-losing BEV in this climate. .. They continued to refine their Escape, CMax, and Fusion hybrids instead. By comparison, Nissan went crazy and put a bunch of $$ in Leaf development, and where are they now? Nissan is getting beat on BEV range by the new GM Bolt which just came out. Leaf is decent, just not the all-out leader in tech at the moment that other newcomers are.

Interesting about VW & Ford collaborating on future EVs. In the past, as in my Ford Focus EV, Ford acted as Systems Integrator and coach builder really while Magna & LG Chem did all the electrics. This way, Ford could study the situation, see what was covered under patents and what they could legally copy in the future, and get some experience with the whole design. ....... At the same time, Ford keeps engineers & scientists busy with the future in R&D aimed at beating other patents, and could either go with in-house designs or continue with some purchased modules, depending on what is most cost effective going forward. Hedging bets! This collaboration is kinda smart.
Originally Posted by PeterPolyol
It's crazy how companies are flocculating into groups, just to beat the other groups
Best use of the word "flocculating" ever. I've never used that word.
 
With all this talk about Mazda's Skyactiv-G & how wonderful it is, it has been surpassed by a cheaper approach.
Why does the Subaru Forester, naturally aspirated (NA), with DI (for 2019) & a CVT tranny, beat Mazda so badly?
Mazda has the "amazing" Skyactiv, right?

AWD 2019 Forester adds DI to the 2.5L, which adds power and MPG. 2019: (182/170)(29/28)(3449/3274)=1.2
2WD Mazda CX5 (187/170) x (28/28) x (3527/3274) = 1.2 (Skyactiv NA, cyl deactivate)
AWD Mazda CX5 (187/170) x (26/28) x (3655/3274) = 1.1 (Skyactiv NA, cyl deactivate)
AWD 2018 Forester (177/170)x(28/28)x(3440/3274)=1.1 (port fuel injection, CVT)

It looks to me like a CVT makes the overall drivetrain more efficient in the Subaru.
Even the Skyactiv tech plus cylinder deactivation couldn't beat the Subaru with a CVT.

GM seems to be best at weight reduction here, for small CUVs.
A CVT (Honda or Subaru's) gives a drivetrain a boost, wasting less of the power flow.
Skyactiv is nice as an engine by itself, or maybe the Nissan turbo VC.
---- Put a Skyactiv engine in an '18 GM Equinox, with a Subaru CVT, and you'd have the number one strategy, hypothetically.
Hypothetical vehicle is around (187/170)x(31/28)x(3400/3274)=1.3 --- assuming a weight gain on the Equinox body due to a bigger engine block and chunky CVT & assuming it would get 31 MPG combined using a Skyactiv-G with a CVT.
 
Last edited:
Originally Posted by oil_film_movies
With all this talk about Mazda's Skyactiv-G & how wonderful it is, it has been surpassed by a cheaper approach.
Why does the Subaru Forester, naturally aspirated (NA), with DI (for 2019) & a CVT tranny, beat Mazda so badly?
Mazda has the "amazing" Skyactiv, right?

AWD 2019 Forester adds DI to the 2.5L, which adds power and MPG. 2019: (182/170)(29/28)(3449/3274)=1.2
2WD Mazda CX5 (187/170) x (28/28) x (3527/3274) = 1.2 (Skyactiv NA, cyl deactivate)
AWD Mazda CX5 (187/170) x (26/28) x (3655/3274) = 1.1 (Skyactiv NA, cyl deactivate)
AWD 2018 Forester (177/170)x(28/28)x(3440/3274)=1.1 (port fuel injection, CVT)

It looks to me like a CVT makes the overall drivetrain more efficient in the Subaru.
Even the Skyactiv tech plus cylinder deactivation couldn't beat the Subaru with a CVT.

GM seems to be best at weight reduction here, for small CUVs.
A CVT (Honda or Subaru's) gives a drivetrain a boost, wasting less of the power flow.
Skyactiv is nice as an engine by itself, or maybe the Nissan turbo VC.
---- Put a Skyactiv engine in an '18 GM Equinox, with a Subaru CVT, and you'd have the number one strategy, hypothetically.
Hypothetical vehicle is around (187/170)x(31/28)x(3400/3274)=1.3 --- assuming a weight gain on the Equinox body due to a bigger engine block and chunky CVT & assuming it would get 31 MPG combined using a Skyactiv-G with a CVT.


Exactly what I posted with our '17 Forester.
That the Subie has a better AWD system than any of the others above is only a bonus although it is the primary reason that people who live in areas of lousy winter weather buy Subarus and not Mazdas or Chevys..
 
Car and Driver (Nov '18) just published an article about the comparison between the new VC-Turbo QX50 & 2 German luxo-CUVs.
Just comparing 3 very similar shaped small AWD luxury CUVs together:
2018 BMW X3 2.0T (248/250)x(24.7/25)x(4156/4000) = 1.0
2018 Audi Q5 2.0T (252/250)x(24.5/25)x(4045/4000) = 1.0
2019 Infiniti QX50 (268/250)x(26.2/25)x(3957/4000) = 1.1
They explained that the QX50 lacks the Stop-Start feature the Audi & BMW both have, so MPG could be even higher in the QX50.
The VC-Turbo's increase in power & MPG simultaneously is obvious here over the competitors, since little adjustment needs to be made for mass.

Oddly, when Nissan took the QX50's VC Turbo & put it in the new Altima thats out now, it mysteriously lost 20 hp. I guess they don't want Nissan getting more hp than Infiniti.
Of course the Altima stomps comparable 2.0T sedans in the class on MPG with that engine.

Maybe the bottom line can be found by listing the thermal efficiency champs:
VC Turbo: 40%, with high power levels....
Mazda Skyactiv-G: 38%, Atkinson LIVC
Honda Accord Hybrid IC engine: 40%, using only Atkinson LIVC
Toyota Prius IC engine: 41%, Atkinson LIVC
Hyundai Hybrid IC engine: 40%, Atkinson LIVC
Mercedes Formula 1 M08 EQ Power+ IC engine: 50%, ok a little expensive to retrofit into my Ford C-Max, so not gonna do it...
 
I've posted this before, but my CX-5 gets much better short-trip mileage than my Impreza ever did. One-hour commute at 55 mph, with stops every 5-10 miles, the CX-5 was somewhat better, but that takes into account that I was 'hypermiling' the Subaru, and just normally driving the CX-5.

Both cars lost MPG quickly past 60-65 MPH, I'd say they were equal, even though the CX-5 is much higher, and with more ground clearance.

The Outback we have is a gas hog.

The CX-5 is a luxury car in comparison to the farm implement Subarus.
The CX-5 is an F1 car handling wise.
The Subies are massively stable in deep, wet snow.
The CX-5's AWD, in the 'testing' I have done, is better at getting all four tires moving at the same RPM. The 2000 Outback I had, with LSD, would blow *all* of the current AWD vehicles off the side of the mountain.

Some objective data:
http://www.fuelly.com/car/subaru/crosstrek
http://www.fuelly.com/car/subaru/forester
http://www.fuelly.com/car/subaru/impreza
http://www.fuelly.com/car/subaru/outback
http://www.fuelly.com/car/subaru/xv_crosstrek
http://www.fuelly.com/car/mazda/cx-5
 
Using the links you've provided, the 2017 Forester (the car my wife commutes in) and the 2017 CX-5 have virtually identical fuel economy.
WRT the CX-5 being a luxury car and the Forster a farm implement along with the CX-5 having F1 handling, one can only laugh.
My wife likes Subies and the Mazda did not appeal to her at all and since she was the intended driver, a Forester it would be.
Ours is also not nearly as thirsty in actual use as fuelly might lead one to believe. The car only sees tank averages as low as those reported on the site in a week of extremely cold weather with ten minute or so warm-ups in the driveway every weekday morning and I do record every tank of fuel used in the car's logbook.
Just filled it up yesterday and it went 445 miles on 14.8 gallons of fuel.
Of course, the new Accord went 498 miles on 10.3 gallons.
This is an example of the reason that I've started calling the Forester the gas pig.
 
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