55 Saves Gas???
I've always heard that driving 55 instead of 60 or 65 saves gas. I'd never really paid attention to just how much gas was claimed would be saved. With prices what they are now, and having to go to the Bay Area on occasion, I thought I really should try it out and see if driving 55 does save gas.
Besides, I'm not often comfortable driving 65, especially on curvy roads where I know I couldn't stop in time if something's stopped in the road just around the corner.
I drove down to the Bay Area Sunday and actually checked out the 55 savings. There were a couple problems I started with:
First; I didn't top off the tank before leaving. I usually don't and usually leave Eureka just a gallon or two short of 3/4 of a tank. This time I probably had a gallon or two more than usual to start.
Second; I didn't really decide to take a serious look at the gas mileage until I was a couple miles out of Eureka so I couldn't remember exactly what the gas gauge was reading when I started. Still, I thought I had a close enough idea of where the needle was when we started off that I should be able to detect a difference in mileage.
I started off setting the cruise control to around 56 or 57 miles an hour. Right off the bat I noticed I seemed to be able to run uninterrupted on cruise control for longer stretches of road than I could going 65, or even 60.
By the time we got to around Garberville, I really felt the gas gauge was higher than it normally would have been but, since I didn't remember exactly where the gauge started out at, or where it normally would be at that point. I couldn't say for sure.
Oddly enough, it seemed like we made Garberville in roughly the same amount of time going 56 or 57 as we did going the normal speed. Around an hour and fifteen minutes. Pretty close, anyway.
Stopping at the Willits Safeway for gas, as we usually do, the gas gauge showed what I figured was about 7 gallons used. Figuring we started with the needle just over the 3/4 mark, and made Willits with it maybe a gallon under the half tank mark, I guessed it at about 7 gallons. Normally I figured it took about 10 gallons. I could never say for sure because I never top off the tank before leaving Eureka.
This wasn't accurate enough, though, since I'm basing this on memory of what I wasn't even sure was right, but we can start over again here.
I reset the odometer to zero and filled up the tank. Since we're staying at the same place this time as last trip, the mileage should be pretty much the same. The only difference will be the speed we'll be traveling at.
Driving to San Francisco and back, it seemed to me the needle was considerably higher than it would have been driving 65 but, again, I couldn't be sure. I never paid enough attention to what the gas gauge indicated at any of the points along the road, except for Willits. In Willits, coming from either direction, the needle shows around a couple gallons less than a quarter tank.
Heading back north to Willits on Monday, I was thinking we probably had a quarter tank more than we would normally have and we must be saving quite a bit of gas. I was thinking maybe we'd save five gallons out of a slightly over 20 gallon tank if this held out.
Heading up Ridgewood Grade north of Ukiah seemed to use up gas quicker. By the time we arrived at the Willits Safeway the needle looked to be maybe a gallon under half a tank. Normally at that point it would be a couple gallons below a quarter tank. I was thinking we could have saved maybe five or six gallons.
I wrote the odometer reading of 266.9 miles, on the receipt. The tank took 13.6 gallons to fill-up. I could crunch the numbers on a calculator later to get miles per gallon. I also realized I still had the receipts from our last trip at home and could just compare the two fuel purchase amounts and that would probably show a substantial difference. Anyway, at this point I was convinced I'd gotten a lot better mileage just from where the fuel gauge was when we made Willits.
I make it home and almost immediately crunched some numbers.
I'd checked the freeway mileage for my truck twice a couple years ago. Both times it came to 16 miles per gallon (11mpg in town). This time it came to 19.6mpg, 20 if you round it off. That's quite a bit better.
Then I checked last trip's gas purchases coming from San Francisco to Willits and compared the numbers: Two months ago, making the same trip but going 60 to 65, I filled up with 14.07 gallons. This time I filled up with 13.6 gallons.
WHAT??? That's only a one gallon difference over 266 miles. Something must not be right.
Looking at receipts from driving Eureka to Willits shows the same thing: I bought 14.43 gallons in April and 13.27 gallons this time, yet I was under the impression I started off this time with a gallon or two more than last time.
I must be missing something. Even though I couldn't be sure of the exact gas gauge readings I would normally have, I felt I'd saved more than just one gallon going each way. Seems to me that my gauge usually shows a gallon or two below the one quarter mark when I reach Willits coming from either direction. This time it showed maybe five gallons more than that.
I know I got better mileage. Crunching the numbers shows almost 20mph compared to the usual 16 going 55-57mph, but something's screwy with comparing receipts. I must be missing something. I just know I saved more than a gallon going each way. Then again, numbers don't lie?
And if you're curious about how much longer it took to get back to Eureka going 55-57, we left UCSF Medical Center at around 3:15pm and arrived at Henderson Rite- Aid in Eureka at about 9:50pm. That's roughly the same time it takes us going 60-65. Go figure.
Anybody up to a return to the 55mph on freeways again? It wouldn't bother me.