Speed vs. MPG charts (post 'em if you got 'em)

[PaleMelanesian]

Originally Posted by ever_green

With a 3.2L Acura TL i used to get better mileage driving at 45mph vs 40mph. This was because i could upshift the automatic tranny to 5th gear at 45mph. The TCU doesn't allow 5th gear below 45mph. This let me cruise at 900-1000rpm achieving 40-45mpg whereas at 40mph i was cruising at 1750rpm and getting 35-40mpg.

So it depends on transmission/gearing and engine/torque.

Here's a trick for Honda automatic transmissions. When you're at 40 mph, do a quick D-N-D shift and it should pop right into top gear. I use that all the time in the Odyssey. Once it's in 5th it will hold it down to 38 mph, you're just tricking it into thinking it was already there.

[MPGranger]

Shouldn't we have separate lines for the separate gears? Wouldn't that truly tell us when to shift? I know it's a lot more data points, maybe I should post a graph first. LOL

[101Volts]

(Edit: This reply was according to a ScanGauge II which read falsely high as I hadn't calibrated it properly at the time.)

I tried a few tests in Moony on some laps of I-80. I didn't use cruise control for the whole segment (It didn't come to mind until after the 65 MPH segment) and it's not the flattest part of I-80, But here's what I came up with counting traffic lights in turning around:

65 and higher MPH (Due to passing vehicles): 31.4
55 MPH: 36.4ish

I've seen over 40 MPG in this van on this portion of road before, One way, Though that wasn't while maintaining a speed of 55.

[PaleMelanesian]

Only a single data point in my old Civic. I regret that I didn't take time to get a full set of data before selling it. 4 runs (2 each way), ~60 degrees and sunny, minimal wind.

60 mph = 40 mpg.

That's just a hair above the Corolla in post 1.

[mikeyjd]

im looking for a ford festiva chart if anyone has one.

[Mcgiiver]

2009 Toyota Tacoma, Xtra Cab, 5 speed manual, 4 x4, 2.7 liter 4 cylinder engine. Fuel consumption measured using Scan Gauge. Higher speed runs, were done over trips on the order of 15-20 miles, 40, and 45 mph runs are shorter, as it's hard to find a long stretch where I can go 40. All numbers reflect relatively flat terrain and transmission in 5th gear. Numbers in chart are average of 3- 5 runs. Results:
40 mph 32.15 mpg
45 33.35
50 29.68
55 28.97
60 23.73
65 23.00

[Saskwatchian]

Finally got enough data points to post my chart.

My car is a 2007 Nissan Versa with the 6 speed manual transmission.

Data collect over two trips south and back. I was surprised to find that the time spent with the AC on was really no different than with the AC of as far as fuel economy is concerned. I am not going to bother differentiating next time I do a set of runs.



The size represents the distance traveled. Most are around 15km. All data points are recorded with cruise control on, engine warmed up, and no traffic on the road. There are 85 data points representing 1301 km traveled.

You can basically ignore the yellow points. They have extra variables like running in a different gear, following a truck, and driving on gravel roads.

[MetroMPG]

Sask - thanks for posting that!

PS: to clarify, are you concluding that A/C makes no difference to fuel consumption?? Or that it just doesn't show up in your data?

[Saskwatchian]

I am concluding that if there is a difference it is well within the noise for my testing method and I am not going to bother differentiate between AC on and off for future tests when I want to see if a mod works or not.

The AC was on when it was warm enough that I needed it to be comfortable and off when it wasn't. I didn't do any ABA runs with/without the AC as I am not planning on altering my use of AC. I differentiated the data since I thought there would be a difference in consumption and I would need to factor in AC or no AC when testing a mod.


As far as ABA testing goes I generally tried to stick to the pattern of 90, 100, 110, 120, 96, 106, 116, 92, 102, 112, 98, 108, 118, 94, 104, 114, 90...

[EcoboosterQ]

Here's some for the Ford F150 EcoBoost:

CleanMPG drove a two-wheel drive model from California to Georgia with a conservative 3.15 rear axle for maximum fuel economy. That doesn't mean they didn't use the truck like it was meant to be used. There were five adults in the pickup for most of the journey plus a cargo box full of camping gear and supplies that pushed the F-150's gross vehicle weight to 7,120 pounds -- 20 pounds over its 7,100-pound GVWR.

Here's a look at CleanMPG's observed Interstate highway steady state fuel economy at different speeds:

70-mph - 22.3 mpg (6th gear with transmission's torque converter locked)
60-mph - 25.5 mpg (6th gear with transmission's torque converter locked)
50-mph - 31.6 mpg (6th gear with transmission's torque converter locked)
45-mph - 33.9 mpg (6th gear with transmission's torque converter locked)
40-mph - 32.6 mpg (6th gear with transmission's torque converter locked)