5 speed vs 6 speed?

[BLSTIC]

The problem I have with *equivalent top geared* 6-speed is that in town if I use all of my gears I spend more time changing gears than I do accelerating, with a 5 speed. Even in my 1.3L Toyota Echo I skip gears often. I can't remember using 4th except when I have to cruise at 30km/h or climb a hill on the highway.

Give me a bigger overdrive 6th though and I'd promise to be your friend

[BLSTIC]

It would, however, be beneficial if your car has poor low-rpm performance.

The NZ-series engines, with baby 210 degree advertised duration cams (probably closer to 190 seat to seat because solid lifters), vvt, and sequential injection, is not such an engine, however.

Nor was my XR6 Falcon. 1450kg car with a 4L engine originally tuned for peak torque at 2000rpm...

[JockoT]

Originally Posted by BLSTIC

I spend more time changing gears than I do accelerating

Doesn't that equate to more time coasting than accelerating? Ideal for good FE.

[BLSTIC]

Not really. At low rpm I can't change gears quick enough to avoid dropping past the rpm I want, which not only means I lose energy slowing down the engine that I just spend accelerating it, but I also lose vehicle energy bringing it back up to speed. And sometimes the decel fuel cut deactivates and the engine starts to idle between gears.

I would prefer a 5-spd auto or a cvt that I can tune in conjunction with the engine ecu. But because Toyota never saw fit to bolt such transmissions into an Echo/Yaris (not in Australia anyway) and nobody can re-tune the stock ECU I'm stuck with what I've got.

[cRiPpLe_rOoStEr]

Originally Posted by BLSTIC

The problem I have with *equivalent top geared* 6-speed is that in town if I use all of my gears I spend more time changing gears than I do accelerating, with a 5 speed. Even in my 1.3L Toyota Echo I skip gears often. I can't remember using 4th except when I have to cruise at 30km/h or climb a hill on the highway.

My mother has a 1.3L Toyota Etios, with a 5-speed manual, and it somewhat bothered me how close its gears feel. I didn't get a chance to test-drive the newer versions with the 6-speed to get a comparison basis.

[bratboy]

So being as wacked as I am I wrote the EPA. I asked to talk to someone about the extra gear better fuel thing. I haven't heard back but I expect it will take some time if I hear anything back at all. So in the meantime I checked out the gov's 1996 tercel ratings and was surprised to see there was no economy difference between 4 and 5 speeds.

But them I checked out our work truck.

https://www.fueleconomy.gov/feg/bymo...ilverado.shtml

checking out the numbers between the v6 and v8's vs total gear counts does indicate extra gears are better. It's all a tad confusing.

[MetroMPG]

EPA probably can't answer your specific question, because...

The answer is: It Depends (TM).

If the additional gear choices permit you to choose an intermediate gear that gives you have a lower cruising RPM than you would otherwise, you'll save a bit of fuel.

If the top gear ratios are the same, and you spend most of your time on the highway, there will be no benefit.

EPA's blanket disclaimer is what? "Your mileage may vary."

[bratboy]

Originally Posted by MetroMPG

EPA probably can't answer your specific question, because...

The answer is: It Depends (TM).

If the additional gear choices permit you to choose an intermediate gear that gives you have a lower cruising RPM than you would otherwise, you'll save a bit of fuel.

If the top gear ratios are the same, and you spend most of your time on the highway, there will be no benefit.

EPA's blanket disclaimer is what? "Your mileage may vary."

I think you are right that their response will be depends...but I also know they have a mountain of information and would be able shed some light on different situations and possible recommendations. Mileage will vary, and it can vary based on a number of factors. I'm pretty sure they could help if they were willing to. And it's not just highway mileage we are trying to save here is it?

[ar5boosted]

5-speeds are definitely stronger from a performance perspective.

The 6-speeds aren't as strong. I find the 6-speed a lot more annoying than a five speed because they are changing so many times. I then find the five speed to ruin my enjoyment of a 4-speed which has too big gaps between the gears.

[bratboy]

Originally Posted by ar5boosted

5-speeds are definitely stronger from a performance perspective.

The 6-speeds aren't as strong. I find the 6-speed a lot more annoying than a five speed because they are changing so many times. I then find the five speed to ruin my enjoyment of a 4-speed which has too big gaps between the gears.

Purely from a technical perspective, this is not necessarily true and it should never be assumed. For Example in GM transaxles:

F40: 295 lbft max
F35: 260 lbft max
F28: 210 lbft max

This would make sense since engine power has increased over the years and gears have been growing over the years. It doesn't make sense that power would go up and strength would go down. The funny thing with the vibe and matrixes is, the 5 speeds are known to fail and the 6 speeds aren't.

I doubt this is true in all cases but it means we should find out before assuming. The dislike for shifting is an entirely different matter and of course is a personal deference thing. I'm just trying to find out what is the best for fuel economy, regardless of the circumstances involved such as extra shifting. Theory and science first for me, then practical decisions.