US Diesel's big splash introduction

My auto doesn’t change at 3000rpm, its mapped to change depending on demand. Mine changes up at 2-2500rpm unless I’m pushing it in which case, I slip it over into manual and force upchanges. You can also encourage an upchange by easing off the power just a tad. Under normal driving the car cruises at 1500-2000rpm.
My (very) old Toyota diesel shifts at 1,500 - 2,000rpm but also changes shift points when floored or when the ECT is activated.
 
I'm talking about foot to the floor changes.
Max performance in auto.

My auto doesn’t change at 3000rpm, its mapped to change depending on demand. Mine changes up at 2-2500rpm unless I’m pushing it in which case, I slip it over into manual and force upchanges. You can also encourage an upchange by easing off the power just a tad. Under normal driving the car cruises at 1500-2000rpm.
 
YouTube videos of the CX-5 2.2D show the AT shifting at about 5000 rpm under maximum throttle. Yeah, that's way past the peak of the torque curve, but you have to consider the gear ratios too.
 
YouTube videos of the CX-5 2.2D show the AT shifting at about 5000 rpm under maximum throttle. Yeah, that's way past the peak of the torque curve, but you have to consider the gear ratios too.

Why don't they stretch out the gear ratios for the diesel so they can stay closer to peak torque? Is this to share a transmission with the gas engine? I noticed the tach at 5000 in the videos also. Even the up-shift only brings it down to 3500 or so.
 
I couldn't find a gearing chart or shift point graph for the diesel, so I created one based on the torque curve Nelson posted a couple pages back.

First I took the picture of the torque curve, blew it up, transcribed the data points into Excel and interpolated data for every 100 RPM. The I used published gear ratios, final drive, tire diameter to calculate road speed vs. RPM for each gear. I cross-checked that against what I see on the tach & speedo in a few YouTube videos of the CX-5 diesel. My road speed vs. RPM numbers within +/-5% of the various data points I took from the videos. The variability is probably due to different tires and inflation pressure and varying speedometer accuracy from video to video. From there, I made a shift point chart showing acceleration (which I normalized) vs. road speed for each gear. The ideal shift points for maximum acceleration are higher than I expected, redline or slightly over for 1-2, and the rest just under 5000 rpm. So I guess the AT is behaving correctly.

Here it is:
http://www.redmc.net/cx-5/shift_points.png
http://www.redmc.net/cx-5/torque_curve.png
http://www.redmc.net/cx-5/road_speed.png
 
Why don't they stretch out the gear ratios for the diesel so they can stay closer to peak torque? Is this to share a transmission with the gas engine? I noticed the tach at 5000 in the videos also. Even the up-shift only brings it down to 3500 or so.

There is no point in staying near peak torque.
The engine makes maximum power at 4500RPM if you shift before that you're just loosing time.

It feels faster to shift earlier in Diesels because the power feels so effortless at low RPM, but in reality, if you want to go as fast as possible you'll need to be at 4000+RPM.
 
I couldn't find a gearing chart or shift point graph for the diesel, so I created one based on the torque curve Nelson posted a couple pages back.

First I took the picture of the torque curve, blew it up, transcribed the data points into Excel and interpolated data for every 100 RPM. The I used published gear ratios, final drive, tire diameter to calculate road speed vs. RPM for each gear. I cross-checked that against what I see on the tach & speedo in a few YouTube videos of the CX-5 diesel. My road speed vs. RPM numbers within +/-5% of the various data points I took from the videos. The variability is probably due to different tires and inflation pressure and varying speedometer accuracy from video to video. From there, I made a shift point chart showing acceleration (which I normalized) vs. road speed for each gear. The ideal shift points for maximum acceleration are higher than I expected, redline or slightly over for 1-2, and the rest just under 5000 rpm. So I guess the AT is behaving correctly.

Here it is:
http://www.redmc.net/cx-5/shift_points.png
http://www.redmc.net/cx-5/torque_curve.png
http://www.redmc.net/cx-5/road_speed.png

excellent chart!

I made one more :)
This is one shows how most people drive a manual diesel. This way of shifting feels the fastest.
In each gear you get a satisfying surge of acceleration that continues right up until the shift.
I'll agree that it is fun driving this way.. but it's much slower than redlining every gear despite feeling 2x faster.
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There is no point in staying near peak torque.
The engine makes maximum power at 4500RPM if you shift before that you're just loosing time.

It feels faster to shift earlier in Diesels because the power feels so effortless at low RPM, but in reality, if you want to go as fast as possible you'll need to be at 4000+RPM.
Hmm, not sure about that. Wait until you overtake and you feel the surge but get to 3000 and it just dies.
 
Hmm, not sure about that. Wait until you overtake and you feel the surge but get to 3000 and it just dies.

I've never driven the skyactiv diesel, just Mercedes, toyota, ford and a pre skyactiv Mazda.
but, I know the feeling that you're talking about.
It's discouraging to feel the acceleration taper off as you're revving higher and making more noise.

It's very tempting to shift to the next gear where acceleration will be increasing with RPM instead of dropping, but the numbers (and automatic transmission shift logic) don't lie.
 
Even though you're in the falling portion of the torque curve, the gearing advantage of holding the lower gear up until 4900-5000 rpm more than makes up for the fact that you're past peak torque. That's why maximum power is a better indicator of 0-60/0-100 time and top speed than maximum torque. The original Honda S2000 is a good example of that. Capable of sub-6s 0-60 mph times despite only 153 lb-ft of torque.

The most enjoyable thing about driving a diesel is cruising effortlessly at lower rpm where it runs quiet, smooth, and delivers good fuel economy, but still having instant torque on tap for accelerating or climbing a hill without a downshift. Even when I've driven small diesel cars in a more sporting manner on twisty roads, I tend to just leave it in a middle gear that lets me ride the wave of torque between 2000-3000 rpm. But when you need maximum acceleration, you still have to rev it out even though it feels like it's running out of breath.
 
I think some are confusing driving for economy with driving flat out.

Its power that gets you up the hill the quickest.
 
Yep. Here's another way to look at the data I posted earlier:
http://www.redmc.net/cx-5/horsepower_gears.png

I overlayed the optimum shift points for a max acceleration run suggested by my previous graph on top of a horsepower curve, trying to illustrate that picking shift points that maximize torque (and thus acceleration) at any given road speed is equivalent to maximizing HP vs. time as you accelerate.
 
No laws regarding that but it's more on economy and profit. SRP of the "top tier" which is diesel is $43k!!!!
We only get 3 variants here. 2.0 PRO (FWD) basic level @ $30k, 2.5 gas AWD @ $37k and the diesel AWD.[emoji4] Each tier has a more accessories or "package" as you called it.

You should ask them why these don't exist there
 
Best thing is to wait until you have a go and see what works for you. I can assure you that revving a small diesel won't get you very far.
 
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