Tested: speed vs MPG - 2006 Toyota Corolla automatic

[MetroMPG]

While I was in Ontario over the holidays, I borrowed my dad's car to collect some speed vs. fuel consumption info.

I learned a couple of interesting things about the car...



Temperature was cool (-4C), and there was a breeze. I'll post the full details a bit later...

Raw numbers: (posted Jan 13/09)

E (mpg US) ... W (mpg US) ... Avg

53.5 ... 60.85 ... 57.2
47.5 ... 53.4 ... 50.5
45.8 ... 53.1 ... 49.5
49.2 ... 54.6 ... 51.9
45.9 ... 51.7 ... 48.8
40.5 ... 45.9 ... 43.2
35.0 ... 40.1 ... 37.6
33.0 ... 36.5 ... 34.8
30.3 ... 32.6 ... 31.5

Conditions, route & methodology (reposted Jan 14 from further down the thread):

Weather conditions: -4C, wind E 9km/h, pressure 103.32 kpa, humidity 68%

Route: 2 lane highway, straight, dry & almost level (11 feet elevation change over 1.6 km / 1 mi.) The road runs SSW/NNE and can be found here: iroquois ontario - Google Maps

Methodology:

Speed was set once per pair of bi-dir runs with cruise control, cancelled with the brake between runs. Car was brought up to speed & leveled off before passing a "start" marker (road sign) where the ScanGauge (not calibrated to this car) was reset. Reading was taken after passing a "finish" marker and cruise was cancelled.

Traffic conditions: There was no traffic in my lane and very little in the oncoming lane. (More than a few runs were done with me being the only car on that stretch of road.) If anyone caught up & overtook me, or if I caught up to another car, I ditched that run and did it again to avoid aero interference.

See also:

• Tested: speed vs. MPG, 2008 Corvette Z06 (505 hp)

• Tested: speed vs. MPG in top gear (1998 Geo Metro / Pontiac Firefly)

• Honda Ridgeline MPG vs speed graph: fuel economy with & without cargo trailer

[Daox]

Very nice. Look forward to the full details.

[MetroMPG]

I just wish the automakers would release this level of info for new vehicles (standardized lab conditions of course).

I'd rather see this than some kind of simulated trip to grandma's house, which is what the EPA does. Or let's say "in addition to".

[groar]

Thanks Darin.

I'm always amazed with the straight line between mph and mpg.

I second the wish to have such data with the car. The normalized conditions should be difficult to find as temperature, humidity and wind do have an influence.

Denis.

[aerohead]

Darin,between 70 and 120 km/h the "curve" is very linear,just as auto engineers claim.Any ecomodder who established a baseline for their own car at any two distinct speeds,and drawing a straight line between those two points on a graph,ought to be able to interplolate or extrapolate mpg at any speed for their car,with a fair degree of confidence.-----------Another valuable tool! Your great graphics and presentation intimidate the hell out of me! "I am not worthy," Thanks mucho,Phil.

[roflwaffle]

What kinda trip mileage are you getting from the Corolla?

[MetroMPG]

Phil: I wonder if we're seeing the slope of the Corolla graph getting less steep as speed increases to 120. That would be consistent with other graphs I've seen, eg:


( source: Speed kills: testing MPH vs. MPG in top gear - MetroMPG.com )

That graph suggests to me what we're seeing is the engine approaching the best BSFC zone as speed, load & RPM rise.

roflwaffle: I didn't really do a lot of driving in the car. I did a couple of mostly rural trips in cold weather (-5 to -10C) that netted mid 40's MPG (US). Left to his own devices, my dad's mileage was 22.4 mpg in wintertime 100% sub/urban driving (from: Win an EM Sticker: guess Dad's mileage (Toyota Corolla automatic). Ends Jan 13. ). Not sure what he's getting on the open road.

[almightybmw]

What kind of road conditions? How long at specified speed was needed to obtain the average? Traffic?
Too many variable my friend. While my GP may lockup at 38mph, here in MT that will not net me the best mileage due to the hills and mountain passes. Dropping my speed from 75mph to 70mph lowered my mpg, just from the decrease in inertia attacking the passes and rolling hills.
I'm guessing you used a scangauge? My dad bought one this last fall, and at 9mpg in the truck he is very motivated to increase that, but has been unable to just because he is already as the limit of his conditions for FE.

Don't take this as an insult or negative comment. Just some of us live in places that just don't allow for amazing FE. Would be nice to hit 36mpg with a full size car, but its just not possible where I live and my driving conditions.

[MetroMPG]

Originally Posted by almightybmw

What kind of road conditions?

2 lane highway, straight, dry & almost level (11 feet elevation change over 1.6 km / 1 mi.)

Weather: -4C, wind E 9km/h, pressure 103.32 kpa, humidity 68%

The road runs SSW/NNE and can be found here: iroquois ontario - Google Maps

How long at specified speed was needed to obtain the average?

However long it took to drive the 1.6 km between markers (road signs) at the given speed.

Traffic?

There was no traffic in my lane and very little in the oncoming lane. (More than a few runs were done with me being the only car on that stretch of road.) If anyone caught up & overtook me, or if I caught up to another car, I ditched that run and did it again to avoid aero interference.

Don't take this as an insult or negative comment. Just some of us live in places that just don't allow for amazing FE.

That may well be. Depends on what techniques you throw at the geography though.

The purpose of the test was to rule OUT as many variables as possible and present some baseline data.

One thing I couldn't avoid was the wind on this day. I'll post the raw data later that shows this.

[Daox]

Originally Posted by almightybmw

Would be nice to hit 36mpg with a full size car, but its just not possible where I live and my driving conditions.

I drove through your general area this summer on a road trip I took and got some amazing mileage (43+ mpg) driving through the mountains with my Matrix filled to the brim with 4 people and luggage. Its totally possible to get great mileage in the mountains.