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US Diesel's big splash introduction
- Thread starter Monterra
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Interesting graph.
Showing what I was saying earlier the optimum change over is around 3.5K revs for most gears, just at the point where the power graph crosses the torque graph.
So nothings changed that's always been the sweet spot for changing up.
My last Xtrail had max power at around 4K revs, 3.8 from memory, and would give an extra surge of power around 3.5K revs.
Showing what I was saying earlier the optimum change over is around 3.5K revs for most gears, just at the point where the power graph crosses the torque graph.
So nothings changed that's always been the sweet spot for changing up.
My last Xtrail had max power at around 4K revs, 3.8 from memory, and would give an extra surge of power around 3.5K revs.
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It works for me.
On both diesels I've had, even Mazda gear the car in top to exceed 2K revs, you are confusing max economy with max performance.
That why I say the car needs another gear, to increase economy, not to make it quicker, 5 gears would probably achieve that.
On both diesels I've had, even Mazda gear the car in top to exceed 2K revs, you are confusing max economy with max performance.
That why I say the car needs another gear, to increase economy, not to make it quicker, 5 gears would probably achieve that.
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- 2022 2.5GT
No im not. Revving the engine to that level is a complete waste of fuel but it's also a complete waste of effort too. Changing up sooner decreases the acceleration time.
Average size
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- 2022 2.5GT
I was meaning compared to a truck engine that max’s out at about 2100 rpm but never allowed for a pedantic.
ANY car, whether powered by diesel, petrol, LNG, hydrogen, electricity, or fairy dust, will get from point A to point B (or speed A to speed B) fastest when the transmission keeps the revs around the power peak NOT the torque peak.
Peak power in the 2.2D comes at 4500 RPM. If you go back to that shift points graph, you'll see the combined effect of torque and gearing on motive force. At 4500 RPM, even though you're way past the torque peak, you're still accelerating harder than you will be after upshifting to the next gear, simply because of the mechanical advantage of the lower gear. Note that the 2.2D makes more torque than the 2.5L at ANY rpm from idle up to its 5200 rpm redline, yet it's slower 0-60/0-100. The 2.5L holds an advantage in peak power and straight line acceleration simply because it revs higher.
I have never driven the Mazda 2.2D, but I've driven a lot of small diesels: VW/Audi 2.0 TDI and 1.6 Bluemotion, Ford/PSA 1.6 and 2.0, later Ford 2.0, and BMW 2.0. They all feel like they're running out of breath as you rev them out because the torque curve is falling at a steeper rate than we're used to from a petrol car. Some more than others. Mazda's own 2.5T in the CX-9 feels like that too. It's not a very fun or satisfying way to drive a diesel. But when you really want maximum acceleration then staying around the power peak is the way you do it.
Peak power in the 2.2D comes at 4500 RPM. If you go back to that shift points graph, you'll see the combined effect of torque and gearing on motive force. At 4500 RPM, even though you're way past the torque peak, you're still accelerating harder than you will be after upshifting to the next gear, simply because of the mechanical advantage of the lower gear. Note that the 2.2D makes more torque than the 2.5L at ANY rpm from idle up to its 5200 rpm redline, yet it's slower 0-60/0-100. The 2.5L holds an advantage in peak power and straight line acceleration simply because it revs higher.
I have never driven the Mazda 2.2D, but I've driven a lot of small diesels: VW/Audi 2.0 TDI and 1.6 Bluemotion, Ford/PSA 1.6 and 2.0, later Ford 2.0, and BMW 2.0. They all feel like they're running out of breath as you rev them out because the torque curve is falling at a steeper rate than we're used to from a petrol car. Some more than others. Mazda's own 2.5T in the CX-9 feels like that too. It's not a very fun or satisfying way to drive a diesel. But when you really want maximum acceleration then staying around the power peak is the way you do it.
You are totally wrong I'm afraid.
I took more care to look at the revs today before the auto changed up, on a slight gradient the change was around 3500 rpm, on a steep hill it was 4,500 rpm.
That's Mazda engineers take on how to provide max acceleration. (braindead
I took more care to look at the revs today before the auto changed up, on a slight gradient the change was around 3500 rpm, on a steep hill it was 4,500 rpm.
That's Mazda engineers take on how to provide max acceleration. (braindead
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Yes average.
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- CX5
One more gear please. I know it's 6 speed automatic transmission. [emoji16]
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- 2022 2.5GT
Must be right then.
It was a hypothetical maximum acceleration run, so I deliberately stopped it at the car's top speed, which is achieved at or just after peak HP in 5th gear. The 6th gear is an overdrive.
But since you asked, here:
http://www.redmc.net/cx-5/horsepower_gears_6th.png
More gears is all well and fine but some vehicles that 7-9 gears can't figure out which gear to be in and hence the constant shifting up and down.
If Mazda makes a 7, 8 or 9 speed automatic in the future, they need to make sure it's done right with correct gear ratios and the computer programming done right so this sort of thing doesn't happen
From what I've read the 7.8.9.10 gearbox problems are usually down to software programming being at fault, the same ZF box fitted in different cars can have variable reports.
Even the Mazda 6 speed auto gets some criticism from UK journalists.
Even the Mazda 6 speed auto gets some criticism from UK journalists.
Pretty much no criticisms here from Australian journalists
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- 2022 2.5GT
No, Im not aware of any either but that 9 speed ZF is a nightmare in both the LR and Honda applications in terms of reliability and operation. It might be good when they eventually sort it out.
Honda here gets CVT but it's got nothing on the Mazda 6 speed
By the time it gets sorted, 10 speed will be more common - cue manufactures that now have this type of transmission:
- Ford/GM joint venture
- Honda
- Lexus
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- 2022 2.5GT
I'm very satisfied with this 6 speed auto. It changes up exactly as I would with a manual keeping those revs right down and with very few exceptions, it is pretty much flawless. The RAV4 auto I had before was quite crude by comparison and I was always willing to change up.
