Driving To Save Fuel

Avoid left turns. While waiting for the left-arrow or for on-coming traffic you are idling. Lay out errands in a clockwise direction like UPS does to maximize right turns. Saves time, idling and pollution too. An irritation as well.

Avoid drive-throughs. Park and walk into the bank, the cleaners, the fast-food joint. The energy you’re using when you park and walk is called calories.

Avoid heavy traffic. Drive at off-peak times if possible or discover an alternate route which might be longer but require less idling.

BRAKES: Every time you hit the brakes you are wasting the gas that bought you that speed.

Ergo: Plan ahead. Choose an appropriate pace. If there’s a red light in your future remove your foot from the gas pedal and coast, keeping an eye out for the least crowded lane, the one without a truck, the one where you might avoid stopping altogether. (Here’s a good game: drive as if you have no brakes.)

At stop-and-go stop signs: Traffic permitting, brake abruptly. Hard on then quickly off. The carry-over momentum will keep you rolling. But you stopped. It’s legal.

On hilly highways allow your car to pick up speed on downslopes and slow some on upslopes. If your cruise control wants to slow your car going down hill, don’t use it. Save cruise for gentler terrain.  (Or learn to play it like an organ.)

LOW TIRES or ones that are out of alignment: It takes more energy (i.e. fuel) to roll a tire that’s underinflated or that’s pointed slightly off line.

The proper pressure range can be read on the little sign visible in the jamb when you open your cars doors. That’s from the car maker. The tire maker inscribed the acceptable range for the tire on the sidewall. They may differ slightly because the car maker chooses limits for comfort. Drivers seeking ultra good mileage (aka hypermilers) go way over the top limit which may save gas but not money because improper inflation is hard on tires. And risky to boot.  Experiment to find a high-ish number that does not make the ride too harsh for your tastes or upset the handling. Low-rolling-resistant tires are increasingly popular.

WEIGHT: Keep in your trunk/back seat only what you absolutely need. No long-term golf clubs or boxes of books you mean to drop off.

DRAG: Remove roof racks unless you actually use them.

At highway speeds the most aerodynamic flow, and therefore best for good mileage is to keep the windows up and use the A/C for cooling. But at town speeds best for good mileage is to keep the A/C off and the windows down. Use your judgment about fumes and unduly hot and dirty air. Just keep in mind that A/C and other “appliances” including headlights cost some fuel.

DIRT: Particularly in dusty environments change the air filter at least yearly. 

MOVING THE CAR: At the mall park equidistant between the shops you’ll visit and walk. Coming home put your car right then where you want it all night. Starting it up to move it later costs fuel.

PEDAL-TO-THE-METAL: Don’t floor the accelerator at launch. So that’s an intuitive saving. Unintuitive but correct: press rather aggressively to reach a moderate speed. Engines vary but all have a sweet spot of max efficiency and getting there quickly is more economical than pussy-footing off the line. Then hang there in the sweet spot.

Find your optimum speed: If you walk down the street with a sheet of cardboard held square to your path even the slightest wind requires some effort from you to keep it straight. More wind; more effort. In a car effort is energy i.e. fuel. Move at a rate of speed that requires optimum energy. (OR, to extend the metaphor, use a smaller sheet of cardboard – i.e. not a slab-sided SUV.) More wind, more muscle. Your car is the cardboard and the wind is its motion. There’s a point at which your vehicle suddenly needs a lot more effort (fuel) to maintain that speed. If you seek the optimum considering both “good time made” and “economy” then drive just below that point where demand surges. Experience or a gadget can find that point for you.  (ScanJet by Linear Logic available at Amazon.com for about $160 will tell you your real time fuel mileage ).

(Drivers who want to really really get low mileage might consider “hypermiling” with maneuvers like Pulse and Glide and turning the engine off at stop lights (like most hybrids do automatically). Some hypermiling ploys are less than safe and some drive other drivers on the road to fist shaking. Check out web advice such as cleanmpg.com)

Anecdote: On a Mercedes-Benz press program in which the BlueTec E-Class clean diesel was introduced prizes were offered for the best fuel mileage back to the San Antonio hotel from the lunch stop, an afternoon’s lope in distance.

All cars started off with full tanks, sealed. Many stopped to pump up their tires to top PSI and spent the hard-riding afternoon slip-streaming 18-wheelers, coasting down hills and sweltering in a closed car under a hot Texas sun with the A/C off.

My partner and I enjoyed a pleasant drive in a cooled interior, chatting amiably, listening to music and driving as speedily as watchful cops allowed. We arrived fresh and early at the hotel. First back. Indeed we arrived two hours ahead of the prize winner who registered 47 miles to the gallon. Our number: 33 mpg. That’s bad?  Asked for a comment when presented with the booby prize, I smarty-pantsed: “You can still buy fuel but you can never buy time.”

And that’s where I stand on hypermiling. I prefer reasonable economy, comfort and hyper-smiling. All an E-Class BlueTec specialty. Effortlessly.

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