Long road trip results

Exactly!
It has been posted before and the numbers are quite easy to figure out.

If you travel for 20miles up a hill at 20mpg and use 1gallon of fuel then you come down the hill and use zero fuel (mpg = infinity) then you have traveled 40miles and achieved 40mpg.

 

Why would removing the hub caps give 3+ MPG increase? I was under the impression that the hub cabs increased mpg's

alfon

 

I just did a road trip from Baltimore, MD to Myrtle Beach SC. Tires were 40/38 psi, and a recent oil change, but other than that, no special driving techniques or add-ons. I was carrying luggage for 9 people, plus a passenger (I was the mule) and the AC was on ALL the time. I also used PWR mode a few times in traffic, and never used ECO mode, just stayed with the pace of traffic. I also do NOT have hubcaps on.

I, um, also drove across a grass median when I was down there and banged up the underside of the front fascia and bent the plastic pan, so the aerodynamics were a tadge worse (pics on that tomorrow.)

Anyway, even with local driving and a trip into Charleston, I got about 48.5 mpg for the whole trip. Not hypermiling, but very decent for heavy duty haulage over about 1,500 miles total.

 

I'm curious about the ScanGuage and the indicated mpg. How does that differ from the onboard computer system's measuring of fuel used? And just for grins, did you happen to keep track of the gasoline you actually put in the tank? I just completed a roundtrip of 1160 miles from SoCal to Redding in NoCal, with about 75 miles of local driving there. This was in my '06, which typically gives me around 53-54 with combined driving and moderate freeway speeds most of the time. The computer is more generous, but I calculate based on the gas I am paying for over the miles driven.
On the trip north, with temps in the high ninties, and 70 mph most of the way, my calculated mileage was 46 (computer: 48.2). On the return, slightly downhill and somewhat cooler as a good portion was at night, but same speeds, I got 48.3, (computer: 48.5). A/C was on the entire trip.
I didn't hypermile, but I didn't beat it to death, either. Wheel covers in place, tires 42/40psi, cruise control used on the open stretches.
So, does ScanGuage blow a little smoke, or what? How much gas did you put in the tank, start to finish?

 

The consensus here seems to be that Prius' mpg display is based on fuel injector volume pumped into the engine, plus an annoying and optimistic fudge factor.

ScanGauge lacks access to this information, at least on many car models. Instead, it estimates fuel consumption from standardized air flow reports flowing on the data bus to which it is tied. And ScanGauge allows user calibration to get rid of any systematic bias such as that built in to the Prius display.

 

I've made four trips between central Indiana and Cocoa Beach Florida in my Prius. I "just drive it," using cruise control most of the time, and going about 75 actual according to GPS (77 on the speedo) when there aren't SUV's slowing me down. I have averaged about 44 mpg for the four trips, two in each direction. This mileage is poor compared to what others are reporting, but I'm impressed. The Prius power train is optimized much more for stop and go driving than steady speed on the super slab, but the low-drag body allows it to get very good mileage, even at highway speeds.

 

What was the average outside driving temperature and speed when the Prius was driving with chains? Can you recall the affects on handling, fuel efficiency, and performance when you had chains on?
Thanks

 

Problem with this is that the ScanGauge offset %age varies from tank to tank. I suspect it's because the SG gets a signal showing 0.02GPH when running battery-only (whereas it shows 0.00GPH in warp stealth). The amount of time one spends in battery-only varies, so the effect of this error will vary. Has anybody figured out how to eliminate this 0.02GPH?

It's more accurate to divide miles on the odometer by gallons pumped. That still relies on the accuracy of the odometer, but all the length-of-warranty class action lawsuits mean that Toyota probably made the odo more accurate than the speedo. Of course both the SG and the HSI rely on the odometer.

Some folks use GPS for distance measurement, which is likely to be more accurate than the odo but may still suffer from interpolation errors. Then the accuracy of the pump is likely to become the factor that limits accuracy.