Is this true? (Instantaneous MPG higher at 60-65 versus 50-55 using DWL)

[SilverCrown9701]

I've been observing my UltraGauge for the past few weeks and I notice that my Instantaneous MPG value goes higher at 60-65 versus 50-55 using DWL and no A/C with a throttle position below 18. It also causes my Average MPG value to rise and my Instantaneous Gallons Per Hour stays relatively the same.

Is it possible that my vehicle gets better mileage at higher speeds with low-moderate throttle position??

[Cobb]

Yes, add some P&G and watch it go even more.

[101Volts]

That's what I've been wondering about my Dad's 3-Litre Caravan. However, I don't have a lot of flat areas nearby that I know about to test this on being in Pennsylvania. I noticed that with the TPS being at 19, 20 or 21 and going at about 70 MPH on a Highway (There are some places where the speed limit is that high in PA) the Instant MPGs actually go in the upper 30s and lower 40s according to the ScanGauge II (Set at -5% or -4%)

That's with tires at 45 PSI, no roof-rack and with the middle and rear seats out.

[ksa8907]

Its possible, but I would challenge you to do more "controlled" experiments and compare data.

[Cobb]

Its has something to do with the map people post that shows a grid pattern, then a bunch of circles like a topographic map with rpms vs engine load. There is a magic speed or gearing vs load you get best mpg, then it drops like a rock.

[SilverCrown9701]

My stock speedometer is only off by about 3 MPH, so I know that my speed isn't much different than what is shown. If I keep my load light and stay in overdrive, then my MPG increases according to my UltraGauge.

I've tried different loads, throttle positions, DWL versus cruise control, acceleration techniques.....it seems that 60 MPH is the magic number but I will continue to test. I will know on my next fillup if it has helped at all.

My Camry has a MAP sensor as well.

[Xist]

Where do HX drivers get their best mileage?

[2000mc]

Sounds like you should create and post a chart to http://ecomodder.com/forum/showthrea...you-15182.html

[oldtamiyaphile]

I don't think I've seen any Speed vs MPG chart for a conventional vehicle where the most efficient speed is 60Mph, especially with an automatic.

Relying on OBD instrumentation for instantaneous fuel consumption is a bit daft if you think about it.

If you really want to know, fill up, drive a 100miles at X speed and repeat.

[MetroMPG]

Originally Posted by SilverCrown9701

Is it possible that my vehicle gets better mileage at higher speeds with low-moderate throttle position??

It's really unlikely.

Watching the "instant" MPG gauge is problematic. It moves around too much to be very useful in predicting overall MPG, and we tend to cherry-pick observations that lead to confirmation bias.

If you look at our collection of speed vs. MPG graphs, the dominant pattern for normal venicles is: best cruising MPG typically happens at the lowest speed in top gear.

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

2002 Camry automatic: