The EPA's estimates for a 2010 Honda Insight are 40 mpg city, 43 mpg highway and 41 mpg combined. After about 12,000 miles with our long-termer, we're averaging 38.7 mpg. Knowing that driving style has a huge impact on fuel economy, I decided to see how good of fuel economy I could get this week.
My goal was to improve on the best tank so far, which was 43.9 mpg from last July. I wasn't planning on doing any extreme hyper-miling techniques or anything, but I was going to drive conservatively and take advantage of the regenerative brakes as much as possible. For the latter, I've noticed by watching the charge/assist gauge for the Insight's electric motor that just slightly applying pressure to the Insight's brake pedal brings up full electric charging for the hybrid battery pack without getting into the actual brakes. It's like our Mini E's regenerative braking, just not as strong.
So for about 100 miles of city driving, I tried to be as gentle as possible on the brake pedal to maximize recharging and minimize the use of the brakes. This also meant I was paying more attention to traffic lights ahead; if one was definitely going to be red, there was no point on rushing up to it and then subsequently have to jam on the brakes (which is what most other motorists do, I noticed.)
On top of the city driving, I did about 150 miles of highway driving. This was on a mostly flat and straight section of highway that had a 70 mph speed limit. I kept to the 70 mph speed limit and used cruise control as much as possible.
The final result for the 252 miles of driving was the best logged economy so far: 45.8 mpg. I used our standard fuel pump recording procedure to determine this, but I also watched the Insight's in-car fuel economy gauge to see how the Insight responded to city and highway driving. For the city driving, my average was about 42 mpg. The highway driving had about a 49 mpg average.
Brent Romans, Senior Automotive Editor
firstwagon says:
11:03 AM, 02/ 5/10
" if one was definitely going to be red, there was no point on rushing up to it and then subsequently have to jam on the brakes (which is what most other motorists do, I noticed.) "
I'm always amazed how many people do that. I see it on the hwy too, as soon as there is an opening they are hard on the gas right up to the next car and then stomp on the brakes.
It's like it's some kind of sport to see how much gas they can burn in how little time.
Impressive numbers on the Insight BTW.
kevinlch says:
11:04 AM, 02/ 5/10
that's the way the real-life mpg should be, Edmunds readers always misled by your mpg figures and think this and this car eats so much gas, but it's just because most of the editors drive the Edmunds fleet more heavy-footed than average drivers
petworthian says:
12:32 PM, 02/ 5/10
Kudos on the great mileage, and kudos, too, for demonstrating that sensible driving techniques really *do* have a demonstrable impact on fuel economy. Simple things like watching your speed, timing to catch lights, accelerating at a moderate rate, using the brakes sensibly . . . all things we should all be doing whenever we drive. When gasoline prices were at their peak the local news interviewed some driver of a big SUV complaining about the high cost of fuel - the woman said something to the effect of "I've even had to start combining my errands into one trip." Well, DUH. I've been doing that for 30 years. A little common sense would go a long way towards reducing our energy consumption.
bodyblue says:
02:58 PM, 02/ 5/10
petworthian, very well said above! This is how cars should be driven on the street....good for the car....good for your wallet......good for safety, there are no downsides to it unless you are a complete moron. Want to race or speed, do it on the track and dont endanger other lives.
mheikka says:
03:13 PM, 02/ 5/10
I've been experimenting with this for some time. While I don't "hypermile" my Insight, I have tried driving more "gently" than usual. I can pick up about 3 mpg that way. Despite the negative press/connotations about "ECON" mode, I stay in that mode all the time, as the performance improvement for not using it is negligible. Our 14k lifetime average fuel economy is 42 mpg overall.
The Insight is finicky about driving styles, external temperatures/weather and accessory use. The "sweet spot" for highest mileage is a dry day between 55-65 degrees F. In those conditions, you don't need to use the heater, A/C, defrosters, wipers or open the windows. As a result, you'll pick up 3 mpg over your running average.
Running the heater (or A/C) or defrosters will cause the small ICE to run more, reducing mileage. The A/C has a greater effect on mileage versus the heater. Using the heater and wipers probably costs 2 mpg. On days below 40 degrees, mileage can drop 4 mpg or more, due to interior heating/wiper demands and more frequent use of the ICE. The batteries seem to lose some of their efficiency at about 40F and seem to provide less "assist".
The worst conditions are rainy, cold, windy days with higher speed uphill freeway runs (over 70mph). The dash computer has shown temporary mileage calculations as low as 32 mpg when you're really pushing it for a while in those conditions.
Overall we've saved over $1000 in fuel alone versus my prior car in about 10 months. Not too bad.
cr_driver says:
04:32 PM, 02/ 5/10
Well romans, do that to other vehicles in the fleet as well.
Be the man .
majin_ssj_eric says:
06:48 PM, 02/ 5/10
I think you will get even better numbers if you stay away from the cruise control. Its been proven that you get worse fuel economy using it than if you just use your right foot....
hondacura4 says:
07:28 PM, 02/ 5/10
Another reason why I don't consider EPA estimates to be the gold standard. Most Honda's currently arent as strong as other brands (May the best car win...wink) in the EPA cycle yet real world data proves that Honda's are quite efficient.
ndahi says:
10:18 PM, 02/ 6/10
These cars are born to pulse and glide since the ICE shuts off when the car is in glide. All the mileage accumulated during the glide is, therefore, free. You can add 15-30% to your MPG when you pulse and glide a hybrid and you get to your destination in the same mount of time. I did some P&G in my S2000 and added 4 mpg to the tank from the prior tank and that is w/o being able to turn the engine off. I am now a believer.
bodyblue says:
07:21 AM, 02/ 7/10
"I think you will get even better numbers if you stay away from the cruise control. Its been proven that you get worse fuel economy using it than if you just use your right foot...."
Proven? I think not. If you are on a hilly road the cruise cannot anticipate the elevation changes and that makes it work harder so then milage can suffer a bit. But on flat roads the cruise adds to your MPG. It just depends how and where you use it. I have a flat freeway commute and I use it when I can....I am on the road at 530 AM so traffic is not bad at that time. At a steady 65 I get in the low 30s with my little V6.
banhugh says:
04:26 AM, 02/ 8/10
for my daily commute, I look for the traffic light far ahead of me and I speed accordingly. If they are red I let the car cruise to the intersection (cut the gas). It helps a lot to improve fuel economy but I understand that sometimes there are drivers that have different ideas about how to approach a red traffic light or have no clue that what is happening 30 ft ahead of them...
zoomzoomn says:
05:59 AM, 02/ 8/10
You know, Honda could be forgiven for their less technical and efficient IMA system, but not for the underdeveloped chassis and hodge-podge dash layout on this car.
mdale007 says:
06:26 AM, 02/ 8/10
The Insight is positioned well now that the Prius is damaged goods. The gas mileage is stunning.
kymerik says:
06:29 AM, 02/ 8/10
lets see...this is a hybrid...38mpg...brand new car...with fancy batteries and regenerative braking and all that nonsense...oh and the biohazard in the trunk, let's not forget that greenies
My car...2004 VW Golf TDI...my last tank, 45.2mpg...and I have a heavy foot, i cant help but hear the whistle of the turbo
So what again is the benefit of this lil POS...slap a small turbo diesel in it and then impress me with 60+mpg
esoterica says:
09:24 AM, 02/10/10
Why doesn't Edmunds perform similar testing on all of their vehicles? This kind of improvement shouldn't be present only in a hybrid.
trjnflip says:
01:02 PM, 02/11/10
I'm glad your brakes worked!