Tested: MPG/fuel economy VS. speed, 2000 Honda Insight, 1.0L lean burn, 5-spd
 

http://forkenswift.com/album/24-shop...-grass-med.jpg

Finally got around to testing the U.F.O.'s speed vs. fuel consumption (at cruise, ideal conditions). This is all in top (5th) gear, with multiple mods in place (listed below) and with hybrid functions switched off (no electric assist/regen/charging during the runs).

For reference, the car's EPA fuel economy ratings are:

EPA city: 49 mpg (US)
EPA highway: 61 mpg (US)
EPA combined: 53 mpg (US)

http://forkenswift.com/album/24-grap...pg-insight.jpg

Weather conditions:

Sept 7th, 2012
Sunny, 20 C
Wind S 5 km/h
Pressure 101.3 kpa
Humidity 71%

Raw numbers:


Speed ........ Set 1 .......... Set 1 ......... Set 2 ......... Set 2 ......... Avg .......... Avg

km/h . mph . W MPGUS . E MPGUS . W MPGUS . E MPGUS . MPG (US) . L/100 km

50 ... 31.1 ..... 129.4 ..... 132.3 ................................................ 130.9 ..... 1.8
60 ... 37.3 ..... 121.7 ..... 121.2 ................................................ 121.5 ..... 1.9
70 ... 43.5 ..... 113.5 ..... 117.7 ..........105.9 ......... 118.4 ........ 113.9 ..... 2.1
80 ... 49.7 ..... 94.2 ....... 101.9 ......... 94.9 ........... 101 ........... 98.0 ....... 2.4
90 ... 55.9 ..... 87.6 ....... 88.3 ........... 86.7 ........... 91.4 .......... 88.5 ....... 2.7
100 .. 62.1 .... 80.6 ....... 82.6 ........... 80.6 ........... 81.5 .......... 81.3 ....... 2.9
110 .. 68.4 .... 66.5 ....... 67.6 .................................................. 67.1 ....... 3.5


Methodology:

All readings were taken in top (5th) gear.

Air conditioning was off, windows were up (passenger side cracked an inch or 2).

Hybrid assist/charging was disabled during the runs.

Car was brought up to speed & leveled off before passing a "start" marker (road sign) where the computer was reset. Reading was taken after passing a "finish" marker.

Lean burn was fully engaged at all speeds except 110 km/h (partially engaged). If the car left lean burn due to throttle movement or an automatic NOX purge, the throttle was quickly adjusted (slightly lifted) to regain lean burn a.s.a.p., and speed was re-adjusted as needed .

Mods in place during test:

• disabled hybrid assist/regen/charge (via "Calpod" clutch switch mod)
• EPS off (electric power steering assist)
• DRLs off (daytime running lights)
• also, the following mods from: http://ecomodder.com/forum/showthrea...-km-18930.html ...
  
• partial grille block
• deleted passenger side mirror
• flat-folded driver's outside mirror (from a Suzuki Swift)
• deleted wiper arms: passenger side & hatchback

Route:

2 lane highway, straight, dry & level (follows river edge). The road runs SSW/NNE and can be found here: 1000 Islands Parkway - Google Maps . Test portion is 1.6 km / 1 mi in length.

Traffic conditions:

There was no traffic ahead in my lane; some traffic occasionally passed in the oncoming lane.

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See also: http://ecomodder.com/forum/showthrea...you-15182.html

You had no problem rolling at 50 km/h & 1083 RPM in 5th gear?

It's OK in 5th on flat ground, sure. But it's the Understatement of the Year (TM) to say: not a lot of power in reserve!

Thats amazing milage you get from that car. Very impressive. So it's acuatually more effecient as a pure gas car compared to hybrid?

If there were identical versions of this car, the only difference being no hybrid components, I would say under limited, ideal conditions a very dedicated driver could probably beat the hybrid car.

A typical driver wouldn't come close to beating the hybrid though.

Most of my driving is with assist/regen disabled. But there are always times you're going to have to brake, and it's better to recapture some of that energy so you can spend it later - strategically - to save fuel.

EG: one drive I do regularly in the summer, I only capture energy for the majority of the trip - I don't use assist at all when the car might otherwise want to. The battery is then as full as possible when I get to a long, steep hill near the end, and that's when I "spend" the captured energy to minimize the fuel economy hit of climbing.

Regen is a wonderful thing.

Did you try P&G with the Insight? I have always wondered if it would be better in lean burn or constant P&G. I.E. 60-90-60 (km/h) P&G or 65 km/h Lean Burn DWL.

Also, would it be better to P&G with the 3rd or the 4th at those speed?

I haven't tried it. One reason I love the Insight is I don't have to pulse & glide to get ridiculous fuel economy at ~80 km/h / 50 mph cruising speed.

If I had to guess though, I'd predict lean burn would still beat 60-90-60 P&G. Others have tried this, no doubt.

EDIT: I did lots of P&G during the 2012 SMCC Montreal fuel economy rally, but only because the course wasn't lean-burn friendly. (Lots of hills/turns/changing speeds, with tight time deadlines on each section.) It was enough to place well in the competition, but it was the worst "fill-up" I've had in the car since I got it.

So is it reallistic to say that with lean burn activated, at 65 km/h, you could see around 117 MPG / 2 LHK, or it is only in perfect test conditions?

Ideal conditions. At that load, if you encountered any kind of hill, you probably couldn't hold lean burn.

Those numbers are on a level road, in warm weather.

I like to go between 65 & 80 km/h on the highway, so I could go at 65 when flat like the 401 :), or go faster (80) in DWL conditions like my commute from Laval to St-Jérôme (autoroute 15).

I hope you're kidding! Going 65-80 km/h on the 401 is going to cause a collision. No amount of fuel you save in your car will be worth getting hurt or hurting someone else.

If you want to drive 65 km/h please find a route that is appropriate for that speed. Don't bother telling me that it's technically legal to do 60 on the 401, that won't matter to you after your car gets rear-ended by someone doing 100.

If you're driving on public roads you should be prepared to drive the speed limit. Going 20-35 LESS than the posted limit will endanger you and everyone else around you, many of whom are going slightly OVER the limit. Roads are safest when everyone is going the same speed.

I routinely drive at 90 on the 401 between Kitchener and Mississauga. No problems at all, in fact, there's a surprising amount of other vehicles at that speed as well. When I first started slowing down on the highway I thought 95 or 90 would be a death wish, now that's the speed that I always drive, it's amazing how often I find others doing similar speeds or even slower (trucks and cars).

Greater speed differentials leading to collisions is understood to be a fact.

But the risk obviously depends on context.

There are times, places & densities where it's clearly safer to go with the flow and other times when not doing so isn't a big deal. (I'm talking about 10 km/h ... 6 mph ... under, here.)

One thing you miss out on is just how sensitive the Insight can be to various almost imperceptible factors - a slight uphill or downhill slope, a change in road surface, head or tailwinds, for all I know the magnetism of local rocks or the phase of the moon. For instance, there's one stretch of road (Calif 70 between Chilcoot & Beckworth) where I never get much more than about 60 mpg, even though it is dead flat and not obviously different from other roads where I'll often be in lean burn getting >100 mpg.

I allways drive 70-80km/h on the highway and i did many long trips on the 17,417,401 (ontario) 15,20,40,50,132 (quebec) and nothing special happened to me:eek:

jamesqf - agreed: it goes without saying that your mileage may vary. When you're burning this little fuel, and reporting the results in MPG (which has drawbacks), very small changes can have big effects on the numbers.

FYI, that's why these runs were done with IMA switched off. This is "engine-only", level road cruising fuel economy. No assist, no background charging, etc.

Guys: since all parties have put in their 2 cents on the highway speed issue, let's please drop it. I'd like to keep this thread on topic. Thanks!

Apologies - it was not my intention to throw this thread off track, but looking back I should have seen it coming...

Back on topic, I had NO IDEA the Insight was so miserly with fuel, very impressive! A friend of mine has a newer Insight, a 2010 I think, and I doubt he sees anywhere near that kind of mileage. I'll have to ask him. He's catching a ride with me to Mont Tremblant tomorrow after work, which will be his first ride in my Eco.

No problem - threads go OT all the time. It's just the way things go. But! This is MY THREAD! So I wanted to try to steer things back. Protective of my babies, I am.

The gen. 1 Insight remains the most efficient internal combustion car ever sold in Canada/US. (Not sure about elsewhere.) It's the efficiency nerd's Bugatti Veyron. The 2nd gen car is quite a ways off.

Have fun at Tremblant. My exotic snowboarding adventure approaches too: I'm heading to Fortune on Friday. :D

great thread, awesome mods and MPG numbers!

subscribed!

Had a look at the figures, you tests is roughly 10% increase in speed is a increase in fuel by 10% based on what I ive been told so good news on my info.

are you using the 128 oz or 160oz gal :confused:

If you look at the legend on the graph you will see he is reporting in both US and Imperial Gallons, as well as L/100km.

BTW, ~153.7 oz = 1 Imperial Gallon

Just for fun ... interesting to see the difference between the real world data you collected and the all theoretical graph I came up with attached bellow

http://ecomodder.com/forum/attachmen...2&d=1363040224

Assumptions I had used:
Gen-1 Insight CdA and Weight
Assumed Tire Crr of 0.01
Including 200 Lbs of fuel and driver
On Flat Level Ground
No Head or Tail Wind
Cool / comfortable day ( low 60's )
Average Humidity & pressure
Assuming average E10 mix of ~35 kwh / gallon energy content
Used Stock tire rolling circumference and gear ratios to get MPH to RPMs
Used BSFC to estimate ICE peak Possible Lean Burn Efficiency at calculated ICE RPMs.

The known other variables that I didn't think of a good way to account for are:
Vehicle electrical loads
Transmission efficiency losses
Real world Operating efficiency vs the ideal peak BSFC point at that RPM

I'm sure I missed a few as well.

In an effort to try and refine my crude theoretical model to make better sense / match the real world data collected.

In watching the 12V system load I regularly see it around ~300W. It goes up and down of course. It depends on what the instantaneous 12V load is. But ~300W from IMA to DCDC would still be about ~326W of ICE parasitic load, if it had to cycle through the IMA battery maybe as much as ~362W of ICE load.

I also tried to narrow down the ICE air pumping losses a bit. The best tool I have is to watch the IMA Volts and Amps while using MIMA to force the ICE to hold certain RPMs ( all while in fuel cut / FAS stationary in neutral ). From the IMA battery side it seems like about ~1 kw of electrical power per 1,000 ICE RPMs. The Actual Air Pumping losses would be less than this as the IMA system is not 100% efficient from battery to shaft. But I've seen studies showing the IMA system ( Motor + Inverter ) combined up to 92% efficient from DC battery load to shaft output. So the actual Air Pumping losses might be around ~0.92 kw per 1,000 ICE RPMs. At 31MPH in 5th gear that's about ~1,058 RPMs and about ~973W of parasitic air pumping losses.

The other interesting thing that came out of that was a better quantification of the air pumping losses ( and IMA Battery electrical consumption ) for running in MIMA-EV-Mode at low speeds. ie. MIMA up to ~10kw IMA assist to move combined with FAS to not use any fuel while doing so. Normally not much use outside of the worst stop and go traffic.

As a purely academic exercise, i decided to see if i could determine the engine efficiency of Lean Burn in a Honda Insight engine from MetroMPG's real world testing. Well, the Former UFO is not stock, so the one constant i had to approximate was the CD. Stock cd is .25, UFO is under .25cd. So take this approximation with a grain of salt. Also the MPG calculator neglects certain km/h values, since the primary values are in mpg. For example, you can not find mpg at 70km/h!

MetroMPG's real world numbers were compared to a theoretical Honda Insight using the Aero/RR/MPG calculator, which was really informative, since any unknown variables are accurately expressed in the real world mpg he got.
[QUOTE=MetroMPG;326520]

Raw numbers: (All values are for Lean burn in 5th gear)
Speed ........... AVG ..........

km/h . mph . MPG (US) ENG EFF% .....%MPG Gain vs non LB

50 ... 31.1 ..... 130.9 ...... 18.7% ................00%
60 ... 37.3 ..... 121.5....... 22.4% ................12%
70 ... 43.5 ..... 113.9 ...... 24.7% ................24%
80 ... 49.7 ..... 98.0 ........ 25.2% ................27%
90 ... 55.9 ..... 88.5 ........ 26.5% ................34%
100 .. 62.1 .... 81.3 ........ 28.1% ................42%
110 .. 68.4 .... 67.1 ........ 25.9% ................39%


You can see engine efficiency goes up with speed, as the engine experiences higher loads and rpm drops. Those are pretty good numbers for an engine experiencing low load on a steady flat road. Lean Burn nearly approaches the engine efficiency of high load in a pulse and glide regimen. Which would be the condition where an engine experiences peak efficiency. And corroborates the story that Lean Burn gives more or less the same mpg as Pulse and Glide at certain speeds.