Wentworth's working hard in the cold

After my post on Monday about short trips and killing kittens, I decided to calculate the potential hit for my own routes. I took mpg samples on my Tuesday and Wednesday obligatory short trips, and was pleasantly surprised. While it's certainly no fun to see each of these trips individually (one of 1.1 miles netted me 30.1 display, ouch!), the fact that I'm apparently able keep the average mileage during all of the week's short trips to about 46.2 displayed mpg (so likely about 44 mpg in real life) means that it won't drag me too far down from 60.

In fact, on a tank spanning two weeks, and thus two Tuesday/Wednesday combos of short trips, I would only have to get slightly above 62 mpg on all my other 433.8 miles to still get about 60 mpg, even with the 46.2 miles of 44 mpg (you can see I'm aiming to fill up about 8 gallons. 433.8 miles + 46.2 miles = 480 miles). On tanks like this week, where I have to drive more than usual, I may only hit Tuesday/Wednesday once on the tank, and I only need a little over 61 mpg on the other 456.9 miles (480 miles - 23.1 miles of Tuesday/Wednesday combo).

This seems like a tall order, and although I've had a couple of 58 or 60 mpgs displayed on the low end, you can see below I've had a good week overall, setting a couple route records, the latest of which was tonight back from work, at 67.7 mpg displayed in 28°F weather. Looking forward to the fillup results anticipated about Monday the 14th!

67.7 mpg over 12 miles


This one was tough, but got 61.9 mpg on the display over 18 miles. Wentworth wouldn't glide for about 12 minutes, it was so cold out - notice the 19°F in the upper right corner of the screen.


68.3 mpg over 27 hilly miles (I'm getting better with warp stealth!)


66.2 mpg over 20 miles

ice + ICE = Math class

Wednesday ended up being another moist, icy, wintry day that necessitated almost constant defroster use, and I knew the ICE (internal combustion engine) would stay on in my first trip of the day, bringing down the mileage. I also have a couple unavoidable short trips for clients, knocking down the mid-50s mpg for a one-way of my main trip to 44.8 mpg or 5.25 L/100km after 15.9 miles/25.6 km.

I knew on the way home, being a night drive on pure ice again, that it would be great to try some hypermiling with few cars on the road.

After I got home, with the return trip tacked on I was back up to 51.6 mpg/4.56 L/100km. This seems disappointing (only 44.8 up to 51.6?!?), but, of course, the drive straight home without detours to clients is shorter at 12.4 miles/20.0 km, and you can't average mpg just like that.

Which brings us to today's math lesson :-)

Here's a convenient formula for calculating mpg for the last segment of driving you've done, like for calculating the way home of a roundtrip drive. Most people need a ScanGauge, but if your car has instaneous mpg like the Prius, try it out. Of course, you can figure it out on your own, but sometimes it's more fun to be lazy and just use whatever you find on the internet!

It supposes a certain amount of information, like that you wrote down the distance traveled and displayed mpg after the first part of your trip. These are represented by distance1 (in miles) and mpg1 in the formula.

You also need total distance traveled in miles and total trip mpg, respresented by distancetotal and mpgtotal in the formula.

Just calculate the second segment of distance, represented by distance2, by subtracting your first leg from the total distance.

Plug it all in...



And I got 64 mpg or 3.68 L/100km on the way home yesterday in freezing temps!