City driving econ: Faster accel in lower gears vs. Slower accel in higher gears?

[Ankleface]

Originally Posted by Piwoslaw

As these are short trips in a mild climate, then maybe the best way to save fuel would be a bicycle or e-bike?

Not a bad idea. I actually walk a lot for most errands, I just mainly use the car when I have to transport unwieldy or heavy stuff.

BTW, have you seen this thread?
ecomodder.com/forum/showthread.php/short-trips-fast-warm-ups-mpg-40244.html

I haven't, thanks!

[Piwoslaw]

Great testing, Ankleface

Wondering whether your route has lots of opportunity for coasting? If yes, then you might benefit from engine-off-coasting with an engine kill switch.

If instead it has lots of ups and downs, and/or accelerationing/braking, then:

• Accelerate at ~80% load,
• Start engine-braking in a high gear as long as possible,
• Turn off the A/C when coasting or idling, but use it when engine-braking (free energy!).

If these are short trips, then maybe you can risk an alternator delete? Depending on the type of alternator your car has, it might be as difficult taking off the accessory belt, or as easy as putting an ON-OFF switch on the alternator's field wire. In the latter case you could turn it on (charge the battery) only when engine-braking, or when the battery's charge drops too low.

Originally Posted by Ankleface

Not a bad idea. I actually walk a lot for most errands, I just mainly use the car when I have to transport unwieldy or heavy stuff.

How my home-built bicycle trailer lowers my MPG

[Ankleface]

Hi there Piwoslaw, thanks for the very useful tips.

Originally Posted by Piwoslaw

Wondering whether your route has lots of opportunity for coasting? If yes, then you might benefit from engine-off-coasting with an engine kill switch.

Interesting option. Yes, there are opportunities for coasting. The only problem is that it's technically illegal here to drive with the engine off. But I'm pretty happy with the trick that I fairly recently learned of coasting to a stop in gear instead of in neutral so that it doesn't have to inject fuel to keep the engine running. I'm sure I could technically coast a bit farther in neutral with the engine off, but traffic is almost always more of a limiting factor than the distance that my car can coast.

Start engine-braking in a high gear as long as possible

Check! Great strategy.

Turn off the A/C when coasting or idling, but use it when engine-braking (free energy!)

This is my favorite, I'm literally afraid I'll wear out the A/C button pretty soon at this rate.

If these are short trips, then maybe you can risk an alternator delete? Depending on the type of alternator your car has, it might be as difficult taking off the accessory belt, or as easy as putting an ON-OFF switch on the alternator's field wire. In the latter case you could turn it on (charge the battery) only when engine-braking, or when the battery's charge drops too low.

Wow, never heard of this trick.

[cRiPpLe_rOoStEr]

Originally Posted by Ankleface

The previous car I mentioned was a Toyota Corolla with a 1.6L 4-cyl that I owned 20 years ago. And now I have a Hyundai i10 with 1.0L 3-cyl. I guess that was sort of an apples-to-oranges comparison because the two vehicles are not really very comparable. And the area where I used to drive the Toyota was a more spread-out city with less congestion and higher average speeds.

Was the Corolla an E120? Well, had it been possible to compare it to a Brazilian Hyundai HB20S, would sort of make more sense than comparing to the i10, as the base version of the HB20S resorts to the very same engine of the i10.

I realize that the two cars aren't really comparable, and the area where I drive most of the time now is different.

I guess you know, accelerating from a standstill takes more energy than to retain a steady speed once you're already rolling. So, even though a small car may be more optimized for heavy inner-city traffic, this environment is much worse regarding fuel economy anyways...

[Ankleface]

Originally Posted by cRiPpLe_rOoStEr

Was the Corolla an E120?

Hmm, I don't think so, not familiar with that variant.

I guess you know, accelerating from a standstill takes more energy than to retain a steady speed once you're already rolling. So, even though a small car may be more optimized for heavy inner-city traffic, this environment is much worse regarding fuel economy anyways...

That's true. I'm not particularly impressed with with my city fuel economy, but other people in similarly sized cars are getting considerably worse in this same environment, so I guess I'm not doing too poorly.

[cRiPpLe_rOoStEr]

Originally Posted by Ankleface

Hmm, I don't think so, not familiar with that variant.

In Brazil it's known as "Brad Pitt's Corolla" because of some ads featuring him.

[Ankleface]

Ah OK, no, mine was 2 generations older than that one I believe.

[cRiPpLe_rOoStEr]

Originally Posted by Ankleface

Ah OK, no, mine was 2 generations older than that one I believe.

So it might've had the 4A-FE engine. An uncle of mine had one with the 7A-FE 1.8L engine. Once in a while I still see some of these running around, often beaten the hell out of, but still going strong.

[Logic]

Originally Posted by Ankleface

Hmm, no because it's a very mild climate, bordering on hot. When I say that the engine is "cold" I just mean relative to its normal operating temperature. But even so the engine definitely is less responsive for the first few minutes of driving, basically it feels like it's running a "choked" air/fuel mixture. So it's a double hit to have to accelerate up the initial steep hill while it's dumping more fuel in at the same time. I'm not sure if I can minimize that initial hit by maybe wasting a bit of fuel at zero load in idle for a few minutes and then accelerating all the way up the hill in 1st gear at lower load than if I were to shift into 2nd.

It's less about the climate and all about having the car at normal operating temperature before you even turn the key.

There are plenty of posts on wall outlet powered block heaters and coolant heaters to be found here.

ie: Plug in to wall when you get home.
It starts on a timer maybe 30 minutes before your departure time. (adjustable)
Don't forget to unplug before turning the key on your already at normal operating temperature car.

[cRiPpLe_rOoStEr]

Originally Posted by Logic

It's less about the climate and all about having the car at normal operating temperature before you even turn the key.

Engine block heaters are mostly unheard of in my country, yet some folks used to place an electric water heater inside the radiator and keep it plugged for a while to ease cold starts in some regions.