What's Your Shifting Algorithm?

[zenfiz6]

Hello, all!

I'll try and submit a "New User Post" soon, but the short story is that, after about a decade of driving an automatic, I'm back to driving a real car: an Audi A4. I'm in LOVE.

But I'm still somewhat rusty and wanted to ask all you pros: How do you determine your shift points?

What I find amazing is that my 2011 Audi has the same speed/engine RPM pattern that I had in the 1987 Legend: 2krpm in 1st is 10MPH, in 2nd it's 20MPH, in 3rd it's 30MPH (plus or minus a couple MPH)... Is this common that the speed in MPH at 2krpm is about 10x the gear number?

Because I know these shift points, I'm using them for driving: Once I get to about 20MPH in 1st, I
upshift to 2nd; once I hit about 30MPH in 2nd, I upshift to 3rd... and because I know all the upshifts should put the engine RPMS at 2k, rev-matching is getting easier for me and my passengers are starting to return their neck braces for their deposits.

But is this the "correct" shift pattern. Ok, wait, let me re-phrase: is this a *good enough* shift pattern for casual driving? Is there a better one? If I shifted earlier (so the new gear would start about 1500RPM) would I get significantly better fuel economy?

Later I'll ask about when the testosterone is flowing and some young whippersnapper thinks he can take me in his Corolla.... But right now I'll act my age.

The nice thing about the A4 is that is isn't the dog the Legend was in 1st gear. I actually can get a decent start in this car.

Much thanks, all!

P.S. so... how do you folks in the metric countries remember your shift points?

(Edit: fixed a smiley)

[4onthefloor]

P.S. so... how do you folks in the metric countries remember your shift points?

Well a metric RPM is double that of an imperial one so it gets a little tricky. I find myself wasting an excess amount of gas and clutch. Damn Canadian cars.


But seriously, I shift when I want to. No different than any other country.

[IMBoring25]

Shifting to put the new gear at 2K is already pretty aggressive. Shifting when the current gear is at 2K is not uncommon when just loafing around.

[watkins]

There is no such thing as a shift point. Shift when you want.

[AHTOXA]

There is no such thing as a shift point. Shift when you want.

...In accordance with the situation, your mood and your goal for the driver (fun, economical, etc).

[tankinbeans]

If your passenger is screaming at you in the next seat and your engine is drowning it out, it's time to shift.

Welcome to the forum.

[theholycow]

is this a *good enough* shift pattern for casual driving?

Yes.

Is there a better one? If I shifted earlier (so the new gear would start about 1500RPM) would I get significantly better fuel economy?

Seems very likely, based on what I know about your car.

Generally (and especially in late model VW products) lower RPM with heavier throttle will be more efficient than higher RPM with closed throttle, and there should be plenty of torque to keep it under 1500 and outrun everybody else on the road...there was in my 2008 VW Rabbit with the normally aspirated 2.5, and the 2.0T is supposed to be quite torquey at low RPM. Higher RPM may be more fun, if you're into that sort of thing.

Enjoy shifting whenever you darn well please.

P.S. so... how do you folks in the metric countries remember your shift points?

Canadians have it tough with their metric RPM, flip top heads, and square tires.

[zenfiz6]

I really appreciate you guys chiming in.

I understand that having a manual transmission means that I get to pick my own shifting routine (part of the reason I bought the car!). But that's *precisely* my issue: I can shift anytime I want, but are there better points to shift at than others? What do I need to know to save gas or make the most of the torque band?

Generally (and especially in late model VW products) lower RPM with heavier throttle will be more efficient than higher RPM with closed throttle...

Is that true for most cars? Now that you've said it, staying low on the power curve might be helpful because power is proportional to gas guzzled/second. How low is too low, though? 1000? 1200?
I think the car idles around 750--800 RPM.

I'm guessing there are things to know like torque/power curves.

...the 2.0T is supposed to be quite torquey at low RPM. Higher RPM may be more fun, if you're into that sort of thing.

I am. But then my grey hair kicks me in the head and I switch from "Crazy Train" to "Hey 19," turn down the volume, and brake frequently and for no reason.

According to the following graph, it looks like life is fun between about 1800--4400 RPM. But I've felt the acceleration a bit more fully nearer the 3k mark. (I haven't been so startled as when my speed-warning went off. I thought I broke the car! )


(I have the dashed-curve.... not yet ready to plunk down $1k to pay APR to start the clock on my next speeder )

If your passenger is screaming at you in the next seat and your engine is drowning it out, it's time to shift.

I thought that's why I should *downshift*

Canadians have it tough with their metric RPM, flip top heads, and square tires.

I've always wondered why we don't just use radians/sec.

Seriously, though: if I know that 2krpm in 3rd is 30MPH.... does the majority of the world using modern units think "oh! 2500RPM in 3rd is 60kph?"
Or am I the only person thinking along these lines? Again, doing this helps me rev-match because I know what I'm gunning for.

Welcome to the forum.

Thank you. I hope to learn a lot and become a better driver by hanging out here.

[theholycow]

Generally (and especially in late model VW products) lower RPM with heavier throttle will be more efficient than higher RPM with closed throttle...

Is that true for most cars? Now that you've said it, staying low on the power curve might be helpful because power is proportional to gas guzzled/second.

Yes, but more so with VWs since 2006 or so. They started using wideband O2 sensors and drive-by-wire throttle. End result, with low RPM acceleration you get wide open throttle (even if you're barely touching the accelerator pedal) but not the open loop enrichment often associated with WOT. This produces exactly as much power as you need without wasting energy on increased engine friction, reciprocating loss, and pumping loss.

How low is too low, though? 1000? 1200?

In my Rabbit there was no such thing as too low. I sometimes shifted by the time I reached 1000RPM, entering the next gear at about idle RPM. I still wasn't holding up traffic, the engine was smooth and quiet, and keeping a lid on my RPM was a major part of getting almost twice the EPA estimate. (More often I'd get up to 1400RPM or so, especially in the higher gears. Either way I ran out of gears by 30mph.)

I'm guessing there are things to know like torque/power curves.

You can study it that way, and doing so is interesting (to me, at least). Logic and theory only take us so far, though. The best thing to do, if you're really interested, is to faithfully keep a fuel log, practice accurate filling habits if you want individual tanks to mean anything at all rather than only being able to look at multi-tank averages, and try different techniques back and forth.

I am. But then my grey hair kicks me in the head and I switch from "Crazy Train" to "Hey 19," turn down the volume, and brake frequently and for no reason.

Both are great songs.

Seriously, though: if I know that 2krpm in 3rd is 30MPH.... does the majority of the world using modern units think "oh! 2500RPM in 3rd is 60kph?"
Or am I the only person thinking along these lines? Again, doing this helps me rev-match because I know what I'm gunning for.

I suspect that it's natural and people think the same way regardless of what units are in play.

[Shadow]

Your car is very similar to mine. Check to see if your car has a mode where you can see shift point suggestions. These shift point suggestions can be turned on or off in the MMI system. There are basically two separate modes if you turn them on. 1- there's a readout on the LCD between the gauges in the instrument cluster that shows the gear you're in and then shows the next higher (or lower) gear to shift into for maximum fuel economy. This isn't just based on RPM alone, it uses other factors as well to determine when it would be best to upshift or downshift. 2- this mode takes the entire LCD screen and it shows the gear number in a large green circle. When it's time to shift, it will prompt you on the screen. in large numbers.

Anyway, you can play around with those modes if you have them (which I'm guessing that you probably do), but keep in mind that your engine has gobs of low-RPM torque, so short shifting is something you can do whenever you feel like it. Of course you can also wind the engine out if you feel like it. That's the fun of driving a manual transmission....it's all up to you and there's no right or wrong.

BTW, post some pics of your car!

[Shadow]

Okay, these aren't very good pictures, but I found them with a quick google search instead of taking pictures of the LCD display on my own car. Anyway, here's what the first shift suggestion indicator looks like:



You can see that you're in 4th gear, and there's a green arrow and green "5" indicating that you should shift into 5th gear.

And this is a picture of the second shift suggestion indicator. This one takes up the whole LCD screen. The gear you're in will be in a green bubble. When that bubble turns yellow, it's prompting you to shift into the next gear. Like I said earlier, it will work for upshifting and downshifting. In the picture below, the "4" just went from a green circle to a yellow circle with the >5 indication, which is telling you that it is time to shift from 4th to 5th. Once you make the shift, you'd see 5 in a green circle.

[zenfiz6]

[VW] started using wideband O2 sensors and drive-by-wire throttle. End result, with low RPM acceleration you get wide open throttle (even if you're barely touching the accelerator pedal) but not the open loop enrichment often associated with WOT. This produces exactly as much power as you need without wasting energy on increased engine friction, reciprocating loss, and pumping loss.

Very very interesting. Although I don't know what a "wideband" O2 sensor is. Either there's oxygen or there isn't.... (unless you mean high-frequency sampling).

How low is too low, though? 1000? 1200?

In my Rabbit there was no such thing as too low. I sometimes shifted by the time I reached 1000RPM, entering the next gear at about idle RPM. I still wasn't holding up traffic, the engine was smooth and quiet, and keeping a lid on my RPM was a major part of getting almost twice the EPA estimate. (More often I'd get up to 1400RPM or so, especially in the higher gears. Either way I ran out of gears by 30mph.)

Wow. I will see what I can do about bringing my shifting RPMs down for the usual city jaunt.

I'm guessing there are things to know like torque/power curves.

You can study it that way, and doing so is interesting (to me, at least). Logic and theory only take us so far, though. The best thing to do, if you're really interested, is to faithfully keep a fuel log, practice accurate filling habits if you want individual tanks to mean anything at all rather than only being able to look at multi-tank averages, and try different techniques back and forth.

*gasp* The scientific method? You can't be serious. That would be... illuminating.

But, being the geek I am, I would like to know a bit of the reasoning behind picking a shift point. The two sides of the coin would be for economic tooling around town and for pinning my partner to the seat. I'm *guessing* that, for acceleration, I want to take it to the top of the torque band and then upshift.... would that be close to being on the mark?

And then there are the shifts when you're going up/down hill and bumper-to-bumper traffic and...

I am. But then my grey hair kicks me in the head and I switch from "Crazy Train" to "Hey 19," turn down the volume, and brake frequently and for no reason.

Both are great songs.

Indeed.

Your car is very similar to mine.

Very cool. Is yours similar to an A5? How do you like it?

Check to see if your car has a mode where you can see shift point suggestions.

It does. According to your picture, I am using the smaller version (I didn't know hit had the big hit-you-over-the-head version.) It seems to like to upshift at anything over 1500 RPM. But I never checked the down-shift suggestion point. I will do that.

But, of course, part of the reason for the post is to find out what other people like to do. If all I was going to do was listen to the car's advice well... I could get the AT for that.

[Shadow]

Very cool. Is yours similar to an A5? How do you like it?

It's not only similar to an A5, it is an A5. Here's a pic:

It does. According to your picture, I am using the smaller version (I didn't know hit had the big hit-you-over-the-head version.) It seems to like to upshift at anything over 1500 RPM. But I never checked the down-shift suggestion point. I will do that.

The "big" version can be accessed with the button on the bottom of your wiper stalk. I rarely mess around with mine, so I don't remember exactly how you get to it. I think you might just have to repeatedly press that button to cycle through the modes.

But, of course, part of the reason for the post is to find out what other people like to do. If all I was going to do was listen to the car's advice well... I could get the AT for that.

Sure, but if you're looking to maximize economy, it would probably be difficult to beat the computer's shift suggestions. If you want to have fun, choose your shift points at any RPM that floats your boat. Personally, I rarely bring my car anywhere near redline. These engines are so torquey down low that there's really no reason to run them near redline. In fact, power tends to start dropping off at around 6000 RPM, so I'll usually shift right about there instead of bringing it up to 7000 RPM. But most of the time I probably don't go much past 3500 or maybe 4000 RPM, even when I'm driving in a "spirited" fashion. And for normal around town driving, I probably shift somewhere between 2000 and 3000 RPM.

[zenfiz6]

Very cool. Is yours similar to an A5? How do you like it?

It's not only similar to an A5, it is an A5. Here's a pic:

Very nice, indeed. This was the car I test drove at the dealership (well, probably not yours)
The salesman decided he wanted to impress me by pinning me to the seat on the test drive.

Ok. I have a broken "X" chromosome. I was impressed.

The "big" version can be accessed with the button on the bottom of your wiper stalk. I rarely mess around with mine, so I don't remember exactly how you get to it. I think you might just have to repeatedly press that button to cycle through the modes.

Yah, I found the Driver Information Screen mode I liked and am not touching it.

Oh: When the instantaneous fuel economy readout says "----- mpg," while engine breaking, does that mean DFCO has kicked in?

Sure, but if you're looking to maximize economy, it would probably be difficult to beat the computer's shift suggestions.

Very true.

But most of the time I probably don't go much past 3500 or maybe 4000 RPM, even when I'm driving in a "spirited" fashion. And for normal around town driving, I probably shift somewhere between 2000 and 3000 RPM.

I've been learning the same thing. Right now my "standard" shifting is still "new gear at 2k" because I know those speed/RPM combos.... but I'll try and knock it down some for the times when I'd like to make the EPA's numbers (right now I'm getting about 25 MPG... not great but not terrible).

[Shadow]

Oh: When the instantaneous fuel economy readout says "----- mpg," while engine breaking, does that mean DFCO has kicked in?

Not sure...I'd have to hook up my scan tool and do some testing. But I will say that DFCO probably occurs more than you think. In the interest of fuel economy, modern cars tend to shut off fuel pulse whenever possible. A true coast situation requires fuel to keep the engine idling, but when you are decelerating while in gear, there's usually no reason to continue the fuel pulse. It's not always that simple, of course, but I do think that the majority of time the injectors are not pulsing at all during deceleration/engine braking.