The other day, I went to the store and bought two of those do-it-yourself bookshelf kits – you know, the ones that weigh a thousand pounds, and that you always manage to drop squarely on your feet as you get them out of the car – yeah, those. Anyways, I got home and forgot to grab them, and so they sat in the trunk of my car for a week. I’ve also got a toddler, so his car seat is permanently strapped into the back seat. Plus, there’s my briefcase, the diaper bag, and we went to Sam’s Club and got a trillion pack of diapers, which I had to put in the back seat, since the trunk was still full of bookshelf kits I hadn’t brought inside yet.
In any case, I probably had about 100+ pounds of excess stuff in my car, in addition to the body weight of whoever happened to be riding in the car at the time. That week, when I went to fill up the tank, I noticed that – even though it was ever so slight – I had to put in a little extra gas. I thought to myself, “Hmm, I haven’t done any extra driving. I haven’t been driving differently. The weather’s been the same, so I haven’t run the air conditioning any more than normal. I wonder what it could be?” When I got home, and finally unloaded the trunk and the backseat, it hit me! It must be all the cargo! Sure enough, the next week, with cargo unloaded, my fuel economy was back to normal.
Here are some Fuel Saver Tips that deal with managing all the cargo in your life.
Tip #1 – Reduce your Cargo Load
It’s a simple fix – I just took the extra stuff out of my car. If you don’t need to be hauling it around everywhere, don’t. Put it inside – garage, storage, dining room table – just don’t keep it in the car. According to FuelEconomy.gov, every 100 pounds of cargo can result in a fuel reduction of 1-2%.
This is relevant for families like mine, but also for a lot of different people. For example, I have a friend who plays in a band, and he frequently loads up the back of his SUV with amps, guitars, keyboards, and other equipment. Any time he just leaves it all in the back of his car between gigs, rather than unloading it for a week, and reloading it only when he’s actually heading to a show, he’s losing out on money that he has to spend at the gas station.
The principle holds true with trucks also. I know a ton of people who use their truck as basically a mobile storage unit, with all kinds of stuff thrown in the back: a couple quarts of oil, gas can, maybe some spare parts for a lawnmower or chainsaw, even lumber. If you load up the back of your truck with firewood, and then go on a bunch of errands before you unload it, you’re pouring money down the drain. Whenever you can, minimize the amount of stuff you’re carrying, and it will help you to maximize your fuel economy.
When the EPA performs Fuel Economy tests, they do it with a load of 300 pounds for cargo and passengers combined. For most people, that’s the absolute minimum! After all, with two passengers both weighing 150 pounds, there wouldn’t be any more room for any kind of cargo, even something like a briefcase. One criticism of the way the EPA does their testing is that this is not a realistic reflection of fuel economy in the real world, but the reason that it is done this way is to ensure that every car gets tested equally. If they weren’t tested equally, it would result in wildly different test results for each way of measuring, and it would ultimately mean that fuel economy estimates weren’t worth the paper they were printed on.
Tip #2 – Cargo Carriers
When you go on vacation, a lot of the time, you’ve got more stuff to take than can fit in your car. For this problem, the cargo carrier was invented. It’s a simple little device that straps to the roof rails on your car, and you can fill it up with all kinds of stuff that you don’t have space for in your car. It’s great.
But if you’re not on vacation, you really should take it off as soon as you get back, before you do any more driving, and here’s why: it increases drag on your car.
In addition to the added weight of whatever you’re carrying in it (see tip#1), cargo carriers increase the air resistance, or drag, that your car experiences when driving. Even though a lot of them nowadays are much more aerodynamically designed, somewhat resembling an airplane’s wing, they are still going to increase the drag on your vehicle, which in turn, will reduce your fuel economy.
Think of it this way: if you’re walking into a strong headwind, it’s a lot easier to stay upright if you tuck your arms in and try to make yourself have as little surface area as possible. Having a cargo carrier on the top of your car is like unzipping your jacket and holding it out, giving yourself wings. It’s going to take you a lot more energy to keep moving forward, and it takes your car extra energy (extra fuel consumption) to propel itself forward. The problem is exacerbated at high speeds, since you’ve got more air to push out of the way.
The best bet is to just go ahead and unload the cargo carrier as soon as you get home from your vacation, and remove it from the car. This way, you won’t have the added weight from the cargo, and you won’t have the drag from the carrier.
Tip #3 – Towing
I don’t know if you ever noticed, but trucks and vans over a certain weight are actually not required to be tested for fuel economy. Why? Because more often than not, these vehicles are used for commercial purposes, towing or hauling cargo, and because there’s so much variation in the amount that they are hauling, there’s no sense in giving fuel economy ratings because they won’t really matter much anyways.
Moral of the story: Just because cargo is not in your trunk doesn’t mean it’s not affecting your fuel economy (this should be obvious, but it’s worth saying). If the engine is pulling it, it’s affecting your fuel economy.
With a trailer, you not only have the weight of the trailer and cargo (which can vary greatly, but even the lightest trailers generally weigh a couple hundred pounds), you’ve also got the drag from air resistance on the trailer, plus drag from tire resistance on the road.
Like with cargo carriers, it’s best for your fuel economy to leave it at home if you don’t need it, but if you do, here are some tips to help maximize your fuel economy while towing.
First, make sure the tires on the trailer are properly inflated. Under-inflated and over-inflated tires will increase the amount of resistance that the tire will have to overcome in order to move forward.
Second, load the trailer evenly, with a slight bias toward the front of the trailer (nearer to the car). What this will do is keep your trailer from affecting the weight distribution on your vehicle as strongly. If you have the rear of the trailer loaded with lead weights, and the front loaded with helium balloons (sounds like a recipe for disaster for those balloons), the trailer’s axle is going to act as the fulcrum of a lever, and it will push up on the hitch where it connects to your car, thus raising your back tires slightly higher. It probably won’t make your rear tires lose contact with the ground, but it will reduce the amount of contact that they have, which will reduce your overall fuel economy.
Third, try to use a trailer that is designed aerodynamically. This is not something you have a lot of control over, but if you can avoid using big boxy trailers, and opt for something more like the aerodynamic design of the cargo carriers mentioned in tip #2, it will help you to reduce the drag of the trailer, particularly at high speeds.
Every little bit helps.
Individually, none of these things are going to solve all of your gas price woes, but each of them will help to shave off a couple of miles per gallon off of your overall fuel consumption. Every little bit helps!
Be sure to check out the other posts in the new Fuel Saver Tips monthly series:
Also, check out this video on the C-Max Hybrid and the C-Max Energi Plug-in Hybrid, presented by our own Frank Towson.