Shifting question: First second then fifth, or use every gear?

[slowmover]

With the trailer in tow — on rural South Central U.S. Interstate — I have to know:

1). At what road speed I can downshift from OD to Direct to maximize braking effect (as a diesel has no closed throttle engine braking); so as to,

2). Undertake any high speed emergency maneuvers contemplated.

As I already know I can undertake throttle-on violent shoulder to median and back wheel cranks at 55-mph, I can’t really be traveling faster than an rpm which allows a downshift so fast it happened yesterday.

Have to bring the engine back in at under 2900-rpm (redline).

As that would be a speed I might (unlikely) undertake to pass a drunk, I don’t sweat it.

But I do bring it up for your own vehicle and habits. No wheelspin, full steering control.

Take the test. A normal load of 75% or better. Wet road.

A severe downslope highway exit with a turn near the end under icy conditions.

A kid can learn to upshift easily. What separates him from men is the dangerous conditions downshifts where brakes alone are a VERY bad idea.

Some of the tankers I drove were 18 shifts on the way up, and another 18 on the way down. Bright, sunny days with no traffic or hills. (Eleven shifts and barely above 20-mph and a big intersection).

Proficiency is up and down. Thus, “every gear every time”, is a basic.

.

[Tahoe_Hybrid]

Originally Posted by Fat Charlie

Sorry, engine braking is still braking. EOC on the downhills, DFCO when you need a little braking.

haha the vehicle is so heavy it speeds up since the engine braking is only enabled on M4 mode it runs

DFCO on Regeneration braking instead


Also mine is differ then the normal hybrid models i can run EV mode to 29MPH while others it turns on at 25mph


I can also trick the REG unit to regenerate while i'm speeding up on the down hill at 88 mph it can generate 60KW sorry not 1.21 jiggawatt

[kurzer]

to get from 2nd to 5th, u have to use the 2nd gear mutch longer, wasting fuel for reving the engine. i use every single gear asap.
skiping gears is a good help for drivers, who are afraid of lower revs. so they can learn about the performance.
and maybe its good for lazy drivers.

but, in some cars i would skip 1st gear, usually.

[PaleMelanesian]

Sometimes I use 12345. If it's downhill I start in 2. Sometimes I'll go 1-2-4-6, oh wait I don't have a 6th Aaaargh I guess 5th will do.

Seriously the gears in this car are so short it's ridiculous. 5th gear hits 2000 rpm at 40 mph.

[T Durden]

Wouldn't it be best to shift so that you are using your engine's "Island of Efficiency"?

I found my Insight's island to be between 2000 - 3000rpm, so I'll shift at 3000 for first and second gear, and the revs drop to about 2000. By the time third gear gets to 3000, I'm moving fast enough to shift to fifth. So 1,2,3,5 for me.

*I'm not using my hybrid battery though.

[Ecky]

Originally Posted by T Durden

Wouldn't it be best to shift so that you are using your engine's "Island of Efficiency"?

I found my Insight's island to be between 2000 - 3000rpm, so I'll shift at 3000 for first and second gear, and the revs drop to about 2000. By the time third gear gets to 3000, I'm moving fast enough to shift to fifth. So 1,2,3,5 for me.

*I'm not using my hybrid battery though.

I always had my best numbers shifting as low as possible.

[Fat Charlie]

Using the island of efficiency and every gear would be right for me if I were under load. Like pulling a yard of topsoil. But even my puny little 1.5l is overpowered for the task of driving me and maybe some groceries around.

Getting up to highway speed involves winding it up through second, then using either third or fourth to get to cruising speed. One end of my drive has an onramp where traffic is unpredictable, I may need to be going anywhere from 60-80 to merge easily. The other end is uphill from a light, where railroad tracks dictate a shift. I'd grab fifth there, but it's an uphill and I generally have cars behind me. The 1.5l isn't so overpowered that accelerating uphill in fifth from 45-50 is polite to others.

[Plasmajab]

Ill toss in a spin on it.

For my ranger:

1st 3.91
2nd 2.24
3rd 1.49
4th 1.0
5th 0.8

1st - 2nd =1.67
2nd - 3rd = 0.75
3rd -4th = 0.49
4th - 5th = 0.20

So lets do a 1 - 3 -5 shift.

1-3 = 2.42
3-5 = 0.69 (Nice)

So shifting from 1st to 3rd is a pretty huge drop in my ranger. You'd have to rev it pretty high to get to 3rd happily, but 3rd to 5th is not as huge of a gap.

In my ranger, 1st gear pretty much is like a "Bull low".. Enough to get the truck rolling but little else.

All the numbers are greek to me. Ill have to do some real world testing. Personally on my western star. YMMV. Basically shifting when the engine is in its peak torque curve with as little rpm as required.

So without "splits"

3rd 1000rpm
4th 1100rpm
5th 1200rpm
6th 1300rpm
7th 1400rpm
8th 1500rpm

For my western star, 1000-1700 is where it makes its peak torque. Basically keeping the engine running in the lowest part of the torque band. But I wonder how this would effect a regular car or truck. Of course the rpms would be higher.. But I think Im going to test this out. Thankfully I just so happened to fill my tank.

[slowmover]

Originally Posted by MetroMPG

I routinely shift 1-3-5 in the MPGiata. It's geared super-sporty-low, even wth the oversize rear tires I put on to get the RPM down a bit.

Sometimes I am seduced into the 1-2-3-4-5 routine, simply because it truly is a fun shifter to use. So I play race-car driver once in a while.

Then I reach 50 km/h / 30 mph and calm down.


I haven't driven the Mirage enough to figure out if skip-shifting will be par for the course, though I have done it more than a couple of times.

I think you (used to, before millions of cretins invaded) be about pack center in this.


I was running tanker with a quite unstable load a few years back. 18-gears up and 18-gears down. Every time. Anything to keep from waking up that monster. ALWAYS at or above 40-tons.

On a major metro street (six lanes) meeting another thus a quite large intersection, I’d have 11-12 shifts completed before clearing that intersection at 22-mph. With 6-7 to go to hit 50-mph.

Y’all crack me up with the impatience. Shifting is just a rhythm. Didn’t any of you learn to sing or play music (means nothing Electric needed)? Did you only learn to perform three bars out of a number?

Correlate the other actions of your life. The ancient, “in it, but not of it”, admonition. For which your car will thank you.



.

[wdb]

Accelerate briskly and skip shifts.

And put an undertray on your Jazz -- you will be flabbergasted at how it makes the front of the car so much more well behaved. Not to mention trimming a few tenths off the MPGs.

And put the lightest wheel/tire combination you can find on it. They get so much more nimble and tossable with light feet!

A properly outfitted Jazz makes hypermiling fun.