Great Milage! 19.8 mpg avg on highway

[schafari]

On my recent trip of 54 miles, I got an average of 19.8 mpg door to door one way. Almost all highway. (95%) Avg speed of 59 mph. At one point, I hit 20 mpg! Again, this was one way with typical driving, cruise around 70mph mostly. Temp of around 70 degrees. Very happy about that!

(I have an 05 V8 HSE)

 

[xcursion]

That IS impressive. Does acutal calculation (not by trip computer) add up to be the same? If it does, I would be very, very, very jealous of your smooth car.........Please do tell us the tire pressure you used.

 

[schafari]

The numbers came directly from the trip computer. I have the tire pressure set exactly at the reccomended front/rear pressures as posted on the driver's side door sticker. (lower b-pillar)

I was so excited, as that is the best I have ever gotten; however, two things to keep in mind. This was only one way, so wind could have helped; however, I was not aware of any sort of wind. Also, I typically only get around 14 in the city which is where I do 75% of my driving. For exclusive trips on the highway, I have only had three in two months and 1,400 miles of ownership.

On the highway previously, I usualy am around 18. (Loaded with camping gear, large wife, and two kids. (Large wife due to her being six months pregnant only. . .so I guess that may mean three kids. . .)

What I think is exceptional, is that the vehicle can get and/or exceed the expected milage on the sticker. This will be the first car I have ever had that even got close to what the mfg said it could.

 

[grommet]

I've hit 19 hand measured MPG a few times... even 20. But it's rare. Maybe downhill all the way, and I'd get better.

 

[xcursion]

I know the mpg figure from trip computer varies from the actual odometer calculation. But I just realize for my last tank (mix city & hwy), trip computer showed 15.9 mpg while hand calculation gave me 12.9 mpg. I am surprise at the hugh differences. Is this normal? Does anyone experience such a differences?

 

[sydeem]

Does anyone know the formula the trip computer uses? I think it has many elements as it shows lousy mileage right after you reset to zero than drive off so I think there are more than one average. Also there is a delay when coasting down hill before MPG really adjusts. I would be surpirsed if one could really get an accurate MPG reading on a short trip.

 

[roland1952]

I have a 4.6 in my RR - the trip computer shows 18+ on a long highway trip but actual calculations show it at 15 and small change.