Save Gas

Old cars are bestApologies if, like me, you’re a Brit and prefer to refer to petrol and diesel, then apologies for today’s post title. But, I’ve noticed a flurry of complaints from Americans about the price of vehicle fuel, recently, and just had to comment. Complaints about the price of gas? I hear the good folks of England, Wales, Scotland, and Northern Ireland exclaim! Yes, indeed, apparently, filling your tank Stateside now costs a staggering $4 per gallon (about 8 pounds sterling!) Pah! You say, us Brits are paying the equivalent of over $10 per gallon these days.

So what’s a driver to do? Save fuel that’s what! But, how? Money-saving expert and pragmatic tide-wad Martin Lewis has a few pointers on his MoneySavingExpert site. In fact, he reckons following his advice could cut your fuel spend by a third and it doesn’t involve overthrowing a government with a penchant for heavy stealth taxes.

There are four key steps to saving money on fuel, Lewis explains:

  • Boost vehicle efficiency
  • Drive more efficiently
  • Find cheaper fuel
  • Get cashback on your fuel

The first of these involves removing any dead weight from your vehicle, detachable seats that never see a derriere could be stored offline, as it were. Roofracks and cycle racks should be taken down unless in use, and any trash, garbage, waste, rubbish lying in footwells, in the boot and trunk and elsewhere should be disposed of or recycled. Lewis reckons decluttering can save a couple of a percent, while ditching the roofrack and do the same.

Other fuel savers include keeping tires at the correct pressure for your vehicle (up to 3% saving), keeping air-con use to a minimum (A/C uses between 4 and 8% of your fuel in hot weather). Lewis’ final efficiency tip is slightly less obvious and possibly doubtful – don’t fill your tank, he says. A car will run just as well on a half-full (half-empty) tank as a full one, apparently. He claims that the weight saving of not filling up every time you drive on to a garage forecourt (filling station), will boost efficiency by about 1%.

I’m not so sure that this stacks up overall, however, because you will end up making twice as many journeys to the filling station, which itself will use fuel not only with the drive, but the stops and starts, and if you get stuck in traffic it could soon counteract that 1% saving. Especially given that being parked with the engine idling for 5 minutes is the equivalent of driving 5 miles, or thereabouts.

Anyway, back to his list. Lewis next suggests that being a gentler driver, rather than a kid-racer can save you up to 60% fuel without cutting your top speed. It’s not about the theoretically optimal approach of accelerating gently up to 56 mph and then releasing the accelerator pedal and cruising back down to close to zero and then slowly accelerating up to 56 again. Rather, Lewis explains, you should ensure you’re driving in the appropriate gear (for stick shift drivers only) and that you should speed up smoothly.

“When you press harder on the pedal more fuel flows, but you could get to the same speed using much less power,” he says, “a good rule is to stay under 3,000 revs [revolutions per minute, rpm].” Conversely, when you want to slow down, use the engine and ease down through the gears, reduce the need to stamp on the breaks. All that hard stopping and starting many drivers do simply wastes fuel. As my driving instructor told me at the start of my first lesson in decades past, “We’re all trying to get from A to B, but there’s no need to rush, be polite to other road users, and enjoy the ride.” (A good life philosophy in general, I thought).

Lewis’ Point 3 means either doing some legwork and hunting down the best buys for fuel or using one of the many price comparison tools on the web. In the UK, we have the aptly and simply named Lifehacker recently highlighted GasBuddy and Gaspricewatch in the US. However, if you find a filling station 30 miles off your regular route that offers a fractional per gallon saving, then give it a miss, the extra 60 miles will most likely counteract the saving. In tip #4, Lewis suggests cashing in on loyalty cards, cashback credit cards, and company savings schemes, which could save a few quid (bucks) too.

There are several other tips we might add to Lewis’ list. If you’re in the UK, agricultural vehicles avoid a certain amount of tax on their fuel, so becoming a farmer could save you money (and, of course, lose you it in other ways). You might be tempted to throw some magic potion, magnets or shiny beads into your tank in the hope of saving a few pennies. Don’t be. From a chemist’s perspective, I’d like to emphasise that drivers should avoid all such scams including so-called catalysts, magnetic gizmos, and shiny beads. Crystals, Reiki, and homeopathic remedies don’t work to fix human bodies, equally they are not going to let you squeeze extra juice from your car.

Some observers suggest switching to compressed gas vehicles, hybrids, electric, and fuel cells etc. These are all well and good, although on the whole simply displace pollution elsewhere in terms of the fuels they use. However, the enormous overall energy and financial cost of replacing even an old car is far, far greater even than maintaining an old banger (lemon).

Finally, here is the killer tip on how to save money on gas – walk or use a bicycle. Aside from the costs of extra carbs you’ll need to sustain you for the journey and the marginal increase in laundry costs for your Lycra cycling shorts, the broader outlook is for an almost 100% fuel saving. Of course, if you commute fifty miles a day, you’re going to have to set the early morning alarm just a little bit earlier to arrive at work on time, but just think of all those poor suckers paying $10 a gallon and listen to the dawn chorus and you’ll feel a whole lot better.

16 thoughts on “Save Gas”

  1. The ideas in this article are pretty good. In my opinion, the most important things to do are change the air filter, keep your tires inflated correctly, remove excess weight from your trunk and passenger seats, and keep your vehicle tuned up.

  2. One additional way to save gas, if you’re packing a few pounds would be to park your car a mile from home and jog to it each morning and evening before hitting the highway, that way you’ll lose some of the lard as well as saving gas. Moreover, once you’ve actually lost those extra pounds, when you drive your car it will have less weight to carry and so run more efficiently.

  3. Petrol Rules. I work for a company that manages and tracks gift cards, and I’ve been following ways to save money on gas on One way to save money on gas is to buy discounted gas cards online. I save gas by converting my car to run off waste vegetable oil. I haven’t paid for gas since January and I’m loving it. If you’re interested you can check out my car on

  4. Nice one John, supports what I was arguing with Dr Burke. Certainly, with the engine idling it’s equivalent to driving the number of miles in distance as time spent idling, coasting is just idling while travelling, so definitely a waste. There is an argument in some parts of the world, that while stuck in traffic one should switch off the ignition to save fuel and cut down fuel. Sounds good in theory, but some big diesel engines waste a lot of energy starting and stopping, not to mention the potential for coking up and the damage caused by constant temperature fluctuations on metals, alloys, and ceramics. Each component damaged and requiring replacement is yet more energy, resources, and money wasted.

  5. Driving on over-inflated tires is as dangerous as driving on under-inflated tires. In the first instance, the tires do not have the traction for which they were engineered and manufactured. In the second case, overheating can occur, shortening the tire’s life or even possibly causing a catastrophic failure.

    Driving in neutral (i.e., coasting) is illegal almost everywhere in the U.S. and probably Europe. The theory is that if the engine is needed in some emergency situation, one must first engage the transmission which is a time consuming one-step or two-step process — and the driver may accidentally engage the wrong gear. There is some who say that this process causes undue wear on the transmission and/or clutch system. Also, this encourages speeding (acquiring enough momentum to make it part of the way up the next hill.)

    Each engine design has a different peak r.p.m. efficiency curve. There is no standard.

    Using the cruise control is illegal in many urban areas. In any event, cruise controls are not designed for fuel efficiency. They are designed to acquire and maintain a certain designated speed. Thus, they waste fuel in effort to acquire the speed in that they accelerate faster than one would do if one does not worry how soon the 50 or 55 mph will be acquired.

    Finally, parking so that one does not have to back out saves fuel — that’s a good idea. And it’s particularly handy if one just robbed the bank.

  6. What’s “downgrade? Neutral? It may be okay elsewhere, but it’s illegal in the UK to drive in neutral…

    35 psi is not the manufacturer’s spec for our car, it’s 39 front 37 back when minimally loaded and 42 and 41 for fully laden.

    As to revs there cannot be a standard value that is optimal, all engines are different and will have different efficiencies at different rpm.

  7. I was coasting on downgrade last week, when cop waved at me as
    he coasted by…….. apparently they have more practice than I.

    35psi is manufacture specs.

    Didn’t understand your engine rev statement.


  8. Dr Burke

    Many thanks for the additional tips. However, isn’t coasting in neutral on the public highway actually illegal. There is an argument in law (and, yes, the law is an ass) that the driver has less control over the vehicle in neutral.

    Also, I was driving yesterday and thinking about the engine revs issue. Surely, it’s totally different depending on the size and weight of the vehicle, the power of the engine and the specific efficiencies of the transmission. Indeed, a petrol engine on a big heavy, old car might be labouring at a certain low rev count but amble along optimally at higher, whereas a diesel is quite happy to run at lower revs with no loss of efficiency. I think the key is to not have the engine screaming at too high a rev count and not to have it grumbling at too low. The sweet spot is probably very different for different vehicles.

    Yesterday, I was getting 51 mpg averaged over 300 metre sections of road in our small diesel at around 2000 rpm, nothing I did, other than breaking, seemed to change that. In fact, breaking seemed to nudge up the average slightly, but I guess that the stopped car was using less than if I were moving.

    The same goes for tires. 35 psi is nowhere near the recommended pressure for our fully laden Ford MPV with all seven seats occupied and luggage in the back.

  9. Just a few additional tips:

    When approaching a stop light, put car in neutral and coast to a stop. No load on engine, means saving gas. If you drive up a hill or over a bridge, put car in neutral on the down side and coast, engage cruise control to continue.
    By all means, use your cruise control and set it for 50 mph or below. This will add 5-10 mpg’s. 1500 rpm is the sweet spot, try to stay near it.
    If you use ethanol, 1/4 of your tank can be filled with water! Good idea about running on 1/2 tank.
    Engage your cruise control when you reach 25 mph and let it do the shifting
    up to 50 mph, much better than your foot on gas petal.
    I brought a Yamaha Zuma and it gets 125 mpg! I use it for short hops
    to the postal office or store and leave my monster Jeep Commander at home;
    although, it has a variable displacement engine that runs on 4 cylinders when cruise control is turned on. But, do buy a cheap scooter for short trips or just cooling off on a hot summers day.

    When you take off from a stop light at reach 25 mph, resume cruise control again. If you had it previously set for 50 mph, it should engage and accelerate
    you up to that speed again, much better than a heavy foot will do. What I meant to say. Always pull into a space to park, that you don’t have to back
    out of, waste gas. If possible, park on the downhill side and coast when taking off. I think a few extra PSI on your front tires, will make them easier to turn
    and more efficient, less friction. But back tires should be at norm, 35psi.

    Enjoy your motoring and respect others.

    dr burke.

  10. Zhu, there is both an optimal maximum speed and an optimal minimum, which is more clearly defined by considered engine rpm rather than actual road speed. For a petrol car that’s around 3000rpm, and somewhat lower for diesel engines. Of course, if we were all driving cars with rotary Wankel engines things would be different again as they convert engine rotation directly into wheel rotation rather than having an intermediate reversing linear motion.

  11. I don’t drive much in the first place but I did pay attention to my speed (lower speed, less gas) and the way I drove. It helps.

    Interesting tips!

  12. You are right about Arizona. For that matter, Southern California, New Mexico, Nevada, Northern Florida and where I am, South Texas. Today, 100 F +.

    I enjoy reading your work.

  13. Yes, all valid points. My mention of avoiding break pads was referring to a study a few years back where they did slow acceleration up to an optimum speed, released the accelerator and then let the car slow to an optimal minimum (56 and 18 mph, I believe it was), not using the gears to drag the car screaming down in speed.

    And, like you say windows up is a saving compared with windows down. I think mythbusters covered this where they showed A/C energy use was pretty much the same as increase in drag with windows down. That said, older A/C units that don’t do climate control could be using as much as 10% of fuel, that’s much more than loss from having the windows slightly open. But open windows don’t cool the car if you’re driving through Arizona anyway, as I recall…

  14. Morning David:

    Where I am, a 100 Deg (F) is not uncommon. That means 130 or more inside the vehicle. Turning off the A/C is not an option. Besides, modern cars actually work more efficiently (fuel wise) with the windows up. So, no matter where you are, the A/C off button is not really a savings.

    Brake pads are less expensive than engine parts. Using the gears to slow down the car is dubious benefit at best. In the end, engine re-working is more expensive. Using the engine to slow the vehicle is torture to a mess of parts that were not designed to slow a vehicle.

    Shopping for cheaper fuel is akin to driving across town to buy pantyhose on sale. I try to ask her, where is the savings?

    Walking or riding a bicycle? Unless everyone else has the same sweaty armpits at the destination, one simply cannot do that. Besides, the cleaning bill goes up — talk about fuel consumption, cleaning body and clothes is the most energy wasteful enterprise in terms of energy use.

    Tires or Tyres. Yes, keep them round. This saves fuel and the four interfaces between the vehicle and the ground last longer — also, the driving on properly inflated balloons is much safer.

    Air Filter, Fuel Filter. Change them regularly, at least every 3,000 miles; they are so inexpensive. Amazing savings here. Along with that, just keep the vehicle tuned — particularly pay attention to the 02 sensor light — when it turns on, fix it or replace it. So many don’t simply because the vehicle will still operate.

    Of course, easy on the pedal at start up. Data shows that generally, the hard starters arrive at the next stop earlier, using more fuel to get there than the easy starters who are right on the tail.

    Almost finally, yes, your fuel (I hear equivalent of $9 or $10) is much more than ours on the other side of the pond ($4 — $5). But, I also an informed (or misinformed?) that about 60% of your fuel costs are taxes while ours are closer to 16% to 20%. So, the fuel companies are making more profits here than in the Isles. I have not figured that out, but the money is going somewhere.

    Finally, I am dumping my Merc as soon as the Smartcar I ordered arrives.

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