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Discussion Starter · #1 ·
I just wanted to let everyone know I achieved some great mileage going 80 MPH (with the flow of traffic mind you). Is it possible that 48.3 MPG is correct at that speed? I reset the MFD before I started my journey on the highway. The cat litter fiend (johnnycrap) doesn't think it's possible. That guy is such a loser!!
 

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Sure, if the route is net downhill. Give more info! How long a trip, was it a round trip, was it very flat.... :D
 

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It passes the manatee smell test. I've done long distance drives and gotten in that ballpark averaging over 75 mph on modest hills.
 

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Discussion Starter · #5 ·
I do think it could have been an anomoly as I only did this once. I believe the MFD is quite accurate. I have measured its calculations to the old method of fill to click and divide the miles. It is sometimes off just by tenths. I am quite pleased with the mileage this vehicle is capable of.
 

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Mr. Prius Anigav said:
Flat... no wind to speak of. No drafting. MFD malfunction? 20 miles from PA border to 287 or thereabouts (nr Rockaway).
48 mpg under those conditions...sure..I've been close.
 

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Definitely can be done on really flat land, once you throw in a hill or two you are pretty much shot in the foot! And it wont last though a tank as your driving conditions are usually never that flat for extended periods.(except for some areas of Texas I went through years ago.... really flat land!)
 

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I have seen that on the MFD also. I have also seen the car go all EV at 55mph for about 3-5 miles on real flat ground too.
 

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48 mpg

I made a profile map from the PA border E on I 80 to the jct with 287, E of Rockaway. This road distance is 40+ miles according to Topo USA, perhaps you were looking at a shorter segment. It is not flat, about 300 feet at each end, and up above 1100 in the middle.

Hills like this don't typically kill mpg, they are very exaggerated in this view (less than 4% slope). My guess is a small but favorable tailwind. Also not much discussed lately is the "corridor effect", traveling in a large group of same speed vehicles that puts you in "good air" even if you are not drafting directly behind a big truck.

DAS
 

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it's possible. I got that mileage doing 70mph on a road trip without due care to mileage.

I've done 80km/h in EV mode (flat with very slight downhil sections). The reason I could do that (with cruise control) was that I had 8 bars so the computer was bleeding out the charge.
 

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Short term, it is possible. Depends on SOC, and with my experience, also depends on if you just filled your gas tank, or it is getting low, as the car will burn fumes from the tank through the intake manifold, bypassing the injectors, thus fooling the readings. But the fumes only last so long, and then you start getting more real readings.
 

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DanMan32 said:
Short term, it is possible. Depends on SOC, and with my experience, also depends on if you just filled your gas tank, or it is getting low, as the car will burn fumes from the tank through the intake manifold, bypassing the injectors, thus fooling the readings. But the fumes only last so long, and then you start getting more real readings.
WOW, learn something new everyday...this is one thing I guess I missed. So, right after fillup, you can get some real HIGH, or LOW readings because of that bypass?
 

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That's my theory. It's the only way I could explain the really high numbers right after fillup. I do know that's how evaporative emissions is dealt with; a vaccume is established in the tank with the intake creating the vaccume.

I could be wrong though.
 
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