[Spargrey]

Hi, everyone. Can anyone give me ideas on how to get good mileage on really short trips? I drive a lot of sub 1 mile trips. Can I get anywhere near good numbers doing that? On 5-10 mile trips, not on the highway, I notice I'm over 50 mpg which is great. But when I drive .75 miles to the grocery store or gym I'm average sub 30 mpg for the trip. Is this avoidable? I would love to get the "city" mileage when driving around town - even if it's in 3 minute stints.

 

[hasarad]

Efficiency requires the ICE be at operating temperature before heavy EV use can occur. That can't happen on a sub 1 mile trip as it takes the engine that long to reach operating temperature.

 

[Spargrey]

Thanks for the input. I wonder if trying to drive in EV mode on those trips would be better. Or would that just require more ICE use on a later date to recharge battery? Also wondering what works better for overall fuel economy, Econ mode or Normal mode. The answer would seem obvious but there seems to be differing opinions here.

 

[insightfully]

High mpg on short drives is possible, but not in way that you can entirely control or predict for each drive. On the same 'short' <5 mile route, I've gotten as high as 85 mpg when factors are 'perfect' and as low as 15 mpg when factors aren't perfect (e.g. cold weather, ICE runs). So even if you keep your drives to 3 mile radius each, you'll see varying mpg results because of factors listed below and how a hybrid responds to optimize energy.

When in EV mode, the display shows '199.99 mpg' and any use of the ICE lowers mpg from there. Getting 199.99 mpg on a short drives COULD happen if the following types of factors align perfectly each time:
- high starting level of HV battery (supports EV for longer time/distance)
- warm weather conditions (minimizes ICE turning on)
- low throttle demand (low speeds and no hills)
...BUT since these factors will vary by drive (especially starting battery level), you'll see different mpg results even when repeating the same short drive.

Let's say your first 0.75 mi drive to the grocery store is in perfect conditions: full battery, warm weather, low speed/throttle, easy terrain... and you get a 'perfect' 199.99 mpg while in EV for the full drive.
- When you end that first drive, battery level will be lower (since consumed in EV mode during preceding drive). This in turn leaves your starting battery level lower for the next drive.
- Since starting battery level is now lower, you won't be able to travel as far on battery alone for your next drive, and the car's hybrid programming will engage to re-build battery level (especially if at/below ~3 bars).
- To re-build battery level, the ICE will need to engage (reducing mpg) OR you'd need 'free' charging from a downhill descent (unlikely).
...NET unless you can start at the same battery level for each drive, mpg results will vary at the end of each drive even if other factors remain the same (temperature, route).

 

[hasarad]

Thanks for the input. I wonder if trying to drive in EV mode on those trips would be better. Or would that just require more ICE use on a later date to recharge battery? Also wondering what works better for overall fuel economy, Econ mode or Normal mode. The answer would seem obvious but there seems to be differing opinions here.

I don't believe you can force EV mode with a cold engine. If you have sufficient battery, you can start in EV (not using the button), but it will last only until you get down to four bars or else exceed the blue band in the power meter.

 

[andrew28]

I try my best to not take the Insight if it is going to be a very short trip (I take uber/lyft or just rack up some extra miles going a longer way). Mainly due to short trips not being good for your car and oil changes need to be done more often.

 

[insightfully]

I try my best to not take the Insight if it is going to be a very short trip (I take uber/lyft or just rack up some extra miles going a longer way). Mainly due to short trips not being good for your car and oil changes need to be done more often.

Maybe I'm thinking about it wrong (open to input...!), but the hybrid nature of the car itself means there are a lot of starts/stops of the gas engine, regardless of drive length. Longer drives (and more on/off cycles of the ICE) definitely make the car more fuel efficient once things are warmed up. But since the gas engine isn't always running for a hybrid, there are 'already' a lot of short trips (or short runs of ICE) built into driving a hybrid, and there seems to be programming that manages the ICE to include 'minimum run times' before the ICE shuts off. I try to combine short trips together in sequence - the same way I would do for a traditional car; but I don't necessarily avoid short drives.

 

[hasarad]

Once the ICE kicks in after whatever initial EV driving one manages to do, it WILL NOT shut off until it reaches operating temperature (which takes a minute or two). That, as well as the use of cabin heat with an un-warmed engine, is what kills mpg on short drives. There appears to be no way around it.

 

[andrew28]

Maybe I'm thinking about it wrong (open to input...!), but the hybrid nature of the car itself means there are a lot of starts/stops of the gas engine, regardless of drive length. Longer drives (and more on/off cycles of the ICE) definitely make the car more fuel efficient once things are warmed up. But since the gas engine isn't always running for a hybrid, there are 'already' a lot of short trips (or short runs of ICE) built into driving a hybrid, and there seems to be programming that manages the ICE to include 'minimum run times' before the ICE shuts off. I try to combine short trips together in sequence - the same way I would do for a traditional car; but I don't necessarily avoid short drives.

I have noticed the minimum run time with the ICE. If I happen to arrive at my destination while it's still on. I would wait in the car until it shuts off before turning off the car. I'm pretty sure short trips would be fine and that Honda has the gas engine properly tuned due to the start/stop nature of the car. I'm just being a little more cautious due to coming from gas cars and this being my first hybrid.

 

[DrThos]

Short trips will always be harder to get a consistent high MPG because of the battery charge level and ICE warm-up.
This is where a Plug-in Hybrid can do a better job with a full charge of electricity.

If there was a way to give our 1.1KW battery a full charge before we leave home... :devil:

 

[PHILBERT]

Short trips will always be harder to get a consistent high MPG because of the battery charge level and ICE warm-up.
This is where a Plug-in Hybrid can do a better job with a full charge of electricity.

If there was a way to give our 1.1KW battery a full charge before we leave home... :devil:

Don't we wish!? :wink:

There are days I jump in, power up (start), and it doesn't run the ICE. I QUICKLY get going in EV MODE before it "thinks too much" and starts the ICE. It probably kicks in somewhere on the road while driving, but my MPG is higher when I don't sit there waiting for the ICE to finish whatever it does to "warm up".

Not a full battery, so it's not that. I think the temperature has to be just right for it to bypass that warmup. Not too hot, and not too cold. Maybe around 60 degrees.

If there was a way to give our 1.1KW battery an extension pack that sat across the entire trunk area, bit was only high enough to meet the opening of the pass-through (2 or 3 inches), and had a "plug-in charger" that charged both battery packs...:devil:

Phil

 

[Wifey'sInsight]

Short trips will always be harder to get a consistent high MPG because of the battery charge level and ICE warm-up.
This is where a Plug-in Hybrid can do a better job with a full charge of electricity.

If there was a way to give our 1.1KW battery a full charge before we leave home... :devil:

or the use of an engine block heater to minimize ICE run time to operating temperature.

 

[DrThos]

or the use of an engine block heater to minimize ICE run time to operating temperature.

I have wondered about using a block heater! living in the cold north, I might add one for winter time and test it out during warmer weather to see if it can shorten the ICE warm up thereby improving short trip MPG's.

Yay - Science!:grin:

 

[pasei]

Don't we wish!? :wink:

There are days I jump in, power up (start), and it doesn't run the ICE. I QUICKLY get going in EV MODE before it "thinks too much" and starts the ICE. It probably kicks in somewhere on the road while driving, but my MPG is higher when I don't sit there waiting for the ICE to finish whatever it does to "warm up".

Not a full battery, so it's not that. I think the temperature has to be just right for it to bypass that warmup. Not too hot, and not too cold. Maybe around 60 degrees.

If there was a way to give our 1.1KW battery an extension pack that sat across the entire trunk area, bit was only high enough to meet the opening of the pass-through (2 or 3 inches), and had a "plug-in charger" that charged both battery packs...:devil:

Phil

Actually mine NEVER turns on the ICE upon start as long as I don't have the heater on, no matter the outside temperature.

 

[pasei]

I was quite disappointed this morning. I went to my dentist 3.0 miles away, suburb driving, flat, 38°F out, no heater except seats', ECO mode, super slow driving with lots of anticipation... Only 37.1 mpg

I suppose the battery pack never warmed up. We can safely assume the seat heaters have a negligible drain on the battery, right?

 

[insightfully]

Actually mine NEVER turns on the ICE upon start as long as I don't have the heater on, no matter the outside temperature.

I experience same, but it also depends on HV battery level. If the starting level is too low for EV, it also triggers the gas engine to start.

 

[insightfully]

I was quite disappointed this morning. I went to my dentist 3.0 miles away, suburb driving, flat, 38°F out, no heater except seats', ECO mode, super slow driving with lots of anticipation... Only 37.1 mpg

I suppose the battery pack never warmed up. We can safely assume the seat heaters have a negligible drain on the battery, right?

Yes, the (electric) seat heaters drain battery less than full climate controlled cabin heating.

In warm weather, the first 3-5 miles of driving tend to be 'lower' mpg than the overall drive. In cold weather, it's maybe 5-7 miles to get to that stability point where the mpg reading represents my actual drive. Past those thresholds, my mpg starts to improve.

Based on what I've experienced, your description of low mpg is not entirely surprising for the short drive in cold weather.

 

[pasei]

I finally plugged in my OBDII reader to my Insight and I've noticed something interesting. When you start the car, after a short distance on the electric battery (something like 0 to 0.5 miles usually), the engine warms up at a constant 1500 rpm for something like 90 seconds. I have also noticed that under "normal" accelerations, the gas engine rpm does not rev higher than 1500 rpm, during that phase at least.

So there comes the idea: in the initial warming up phase, it may be a good idea to use these 1500 rpm instead of losing them, which would mean having normal/fast accelerations even if it means breaking harder (warms up the battery too this way!). This is as opposed as driving as slow as possible when the engine is cold. (Of course, don't do that when it's -5°F). It's possible that the battery gets a little less charge during that initial 90 seconds but I haven't noticed it gets charged that much anyways.

Thoughts?

 

[Moviemike]

.......So there comes the idea: in the initial warming up phase, it may be a good idea to use these 1500 rpm instead of losing them, which would mean having normal/fast accelerations even if it means breaking harder (warms up the battery too this way!). This is as opposed as driving as slow as possible when the engine is cold. (Of course, don't do that when it's -5°F). It's possible that the battery gets a little less charge during that initial 90 seconds but I haven't noticed it gets charged that much anyways.

Thoughts?

The energy flow screen could give ya information on how the 1500 rpm is shared between battery charging and the wheels.

I prefer some extra rpm early in the drive on cold days to warm the ICE quicker. A normal operating temperature of the ICE gives better ICE efficiency, ,which contributes to a warmer cabin sooner (with some heater use), which in turn seems to encourage the HV battery to charge up a little faster and do the discharge - recharge cycle faster as well. (This fast cycling seems to be key to my terrific mpg at temperatures in the low 60's and above.)

I've also noticed that with the system at a normal operating temperature, if I turn the car off for a brief period and then turn it on again, it will always go through a long ICE-on period, an apparent electronically mandated "warm-up". However, if under similar conditions, I leave the car on (sitting in it but not moving) no additional long ICE on period occurs, helping mpg.

 

[pasei]

I finally plugged in my OBDII reader to my Insight and I've noticed something interesting. When you start the car, after a short distance on the electric battery (something like 0 to 0.5 miles usually), the engine warms up at a constant 1500 rpm for something like 90 seconds. I have also noticed that under "normal" accelerations, the gas engine rpm does not rev higher than 1500 rpm, during that phase at least.

So there comes the idea: in the initial warming up phase, it may be a good idea to use these 1500 rpm instead of losing them, which would mean having normal/fast accelerations even if it means breaking harder (warms up the battery too this way!). This is as opposed as driving as slow as possible when the engine is cold. (Of course, don't do that when it's -5°F). It's possible that the battery gets a little less charge during that initial 90 seconds but I haven't noticed it gets charged that much anyways.

Thoughts?

Now that I have the Amp going in/out of the battery pack with my OBD reader, I need to correct the above statement. The ICE absolutely charges the battery whenever idling (during warming up). The second you are accelerating, the ICE does not produce enough Watts and the battery is depleted, but then when you slow down, the ICE charges the battery along with regen braking. So, having fast accelerations as I suggested above decreases a lot the battery (something like 5% instantly) but then you have more cruising time to recharge it. So I still don't know if it's the best technique. But I've been trying different things and it's hard to tell if anything makes a difference. I think idling at a red light during the warm up is the worst, but if you're moving, pulse and glide or snail-style, you should be OK.