Optimum acceleration with auto-manual

[Snowman9000]

I recently bought a new 2013 Focus SFE (fuel economy edition), with the base motor and an electronically clutched and shifted "manual" gearbox. I'll do a review of the car in another thread after my next gas purchase.

The trans on this edition does not have any manual shifting option. You put it in D, and drive. But it is a clutch and gearbox, no slush-box. Can we treat it as if I'm shifting a manual trans, and discuss the best rate of acceleration?

Here's how it shifts. If I accelerate conservatively, it will upshift at ~2100 rpm. That is the lowest shift RPM it will do. This puts it into 6th at about 41-42 MPH. But like an AT, if I accelerate more quickly, the shift RPMs go up. So my choices are somewhere along a sloped line if you were to plot it on a graph. i.e. I cannot accelerate quickly yet have it upshift at 2100 rpm. Well, I can sort of fool it on the 5-6 shift by momentarily letting off at 42 MPH, but that is not as effective or practical in the intermediate shifts.

So, what do you think?

[user removed]

2011 Fiesta here. I've driven it close to 18k miles of the 21k total it has now. I generally accelerate with the flow of traffic here. My shift points are probably a little higher than your Focus with my 1.6 liter engine needing higher revs for decent acceleration. My mileage speaks for itself.
I think up to 3k in 1st gear and lower RPM in higher gears would be a good place to start.

regards
Mech

[Joggernot]

I lift my foot very briefly in the Accord at 2000-2200 rpm and it will shift. 42 mph is the slowest it will go into 4th gear by lifting my foot. I "force" a shift this way on all drives.

Joggernot

[ps2fixer]

My corolla I can get to shift around 2k rpm (no rpm gauge, so I don't watch it on my scanner very often). I get it to shift into lockup (automatic) at around 43mph, and hold the gear down to around 39mph before it down shifts. 45mph = ~1600 rpm and 50-55mpg instant readout.

I'm not sure about the other brands, but I have read about people that offroad their toyota trucks overriding their ECU and adding in a 6 way switch to manually shift the electronicly shifted auto transmission. You just have to add dummy loads for the ECU to be happy.

Their setup normally is:

1. ECU / factory setup
2. 1st gear
3. 2nd gear
4. 3rd gear
5. 4th gear
6. ECU / factory setup

and a seperate switch for lockup. Been wanting to this this for a while, but haven't yet.

[mechman600]

Acceleration rate vs economy has been discussed a lot in this forum. Generally speaking, it probably doesn't make much of a difference as long as you do not accelerate so fast that your engine goes into open loop/enrichment.

[Snowman9000]

When you say lockup, I'm confused. Mine has no torque converter. Just a clutch and gearbox. AFAIK, anyway.

[Snowman9000]

Originally Posted by mechman600

Acceleration rate vs economy has been discussed a lot in this forum. Generally speaking, it probably doesn't make much of a difference as long as you do not accelerate so fast that your engine goes into open loop/enrichment.

To pick nits, in my case it's acceleration rate AND shift points, and they are linked. I can't try different rates while always shifting at say 2500. The answer might still be that, within reason, it doesn't matter. But it'd be interesting to know.

[mechman600]

Acceleration rate and shift points are ALWAYS linked with an automatic. Shifting at a higher RPM does not affect economy that much. It's what you do when it's time to slow down that really matters (coasting vs braking hard). For example, on an on ramp onto the freeway revving out to 4K to get up to speed is likely as efficient as accelerating slowly (and much safer because you are not holding up traffic).

You have the "manumatic advantage". Because you have no torque converter, you are accelerating efficiently no matter how slowly or quickly you do so, except of course if you really stand on it and put the engine into open loop.

[Snowman9000]

Originally Posted by mechman600

Acceleration rate and shift points are ALWAYS linked with an automatic. Shifting at a higher RPM does not affect economy that much. It's what you do when it's time to slow down that really matters (coasting vs braking hard). For example, on an on ramp onto the freeway revving out to 4K to get up to speed is likely as efficient as accelerating slowly (and much safer because you are not holding up traffic).

You have the "manumatic advantage". Because you have no torque converter, you are accelerating efficiently no matter how slowly or quickly you do so, except of course if you really stand on it and put the engine into open loop.

Great, thanks! I guess that is what everyone else is saying too. Well, that frees me up from aggravating the people behind me.