CNNMoney has compiled a list of gas saving myths and asked Consumer Reports and Edmunds.com to debunk them. Here’s the list:
#1. Fill your tank in the morning
Consumer Reports says that the temperature variation in a single day isn’t really significant enough to affect the gas, so you might as well stay in bed.
#2. Change your air filter
“Modern engines have computer sensors that automatically adjust the fuel-air mixture as an increasingly clogged air filter chokes off the engine’s air supply.”
#3. Use premium fuel
“When sensors detect regular instead of premium fuel, the system automatically adjusts spark plug timing. The result is a slight reduction in peak horsepower – really, you’ll never notice – but no reduction in fuel economy.”
#4 Pump up your tires
“According to on-the-road driving tests by both Consumer Reports and auto information site Edmunds.com, underinflated tires reduce fuel economy, so proper inflation is key.
But you should never over-inflate your tires.”
#5 To AC or Not To AC
At most speeds and in most vehicles, A/C use drains slightly more fuel than driving with the windows down, contends David Champion, head of auto testing for Consumer Reports. “My final take on is that it’s very close,” says Phil Reed, consumer advice editor for Edmunds.com. “It’s hard to measure the difference and every vehicle is different.”
#6. Bolt-ons and pour-ins
“… if there really was an additive that made gas burn up more slowly, it wouldn’t be sold over the Internet one bottle at a time.”
There’s more detailed info at CNNMoney, but as far we’re concerned, the best way to increase your fuel economy is to slow down, stop running up on people’s ass and then slamming on the brakes, and don’t weave from lane to lane trying to find the fast one. They’re all slow. Such is life. Relax.
6 gas saving myths [CNNMoney] (Thanks, Aaron!)
(Photo: meghannmarco )
Allot of truth in there, but it seems that they forgot the most obvious thing – stop driving like a twit. It never fails to amaze me all the people that drive like they’re in a race (jackrabbit driving from red light to red light, agressive lane changing to gain that extra 10 feet, driving at 80MPH) and then have the gall to complain to no end when it comes to the resultant MPG they’re getting.
Slow down, drive economically, and you’ll get better MPG. If your too impatient to make an effort, then you have no bloody excuse to complain about your low fuel milage.
Last, I’ll agree that this article is way off base with the premium fuel issue – if your car REQUIRES premium (supercharged, turbocharged, or otherwise high compression) you can almost count on worse fuel milage by trying to use lowtest gas. My last car was supercharged and it ran *terrible* on 87 octane – it’d run on it, but the computer retarded the timing so much (to avoid engine damage from detonation) that you had to use about 25% more throttle to gain the same amount of power. In the end this resulted in much worse milage, and vastly less horsepower.
If you can’t afford to put premium fuel in a car that requires it, consider another car, don’t just think your going to get off easy and buy the cheap stuff, because chances are you’re only screwing yourself.
@cerbie: Where do you shop – or, what do you drive??? K&N air filters are <$50 online(for OEM replacement, not the fancy ones), and all my airfilters have run $12-15 each for Hondas and Saturns. The only <$10 filters I’ve seen were for cars built 20 years ago. Not to mention most air filter changes are recommended at 12-15k miles or one year.
On octane ratings, definitely RTFM – you might be surprised that your car may need 89 octane. It’s not just the Ferraris and Lambs that need higher octane. My motorcycle runs on 89 minimum, and it’s not a racing bike. You also need to pay attention at the pump. Many cars need 87 minimum, even the smaller, cheaper ones. That means, if you’re off the beaten path, you may have to buy mid-grade, since many gas stations off of major highways will have 86 regular, while stations in well traveled areas have 87 regular. I noticed that on a motorcycle trip down old 2-lane highways in west Texas, where the Premium was 90 octane, while it was 92/93 octane at the same chain on I-35.
Please stop perpetrating the myth of high octane and performance!
Octane rating has nothing to do with the amount of energy in the fuel!
A higher octane rating does not provide better horsepower, torque or fuel milage.
Octane rating does not affect engine performance unless you use a fuel that has an inappropriately low rating compared to the requirements of vehicle you are putting the fuel in. Putting 91 octane in a vehicle that only requires 87 will get you nothing except poorer. Conversely, put a 50 octane fuel in any gasoline engine and watch the engine self destruct… quickly.
Octane rating is a measure of the “anti-knock” properties of the fuel. A low-compression engine can get away with low octane, but higher performance engines run at higher compression ratios and might/will cause auto-ignition of the fuel-air mixture before the spark plug fires at an appropriate time/angle. This pre-ignition causes lower fuel milage, excess noise, loss of power and possibly engine damage if the effect is severe enough.
If you are driving an “average american sedan” then an 89 rated fuel will usually work fine in your engine. If you are driving a Ferrari and try using 89 octane it might work well under light engine loads, but step on the throttle and watch the engine self destruct.
Diesel fuel’s octane rating equivalent is usually in the teens (15-20 rating but diesel is rated by cetane). The difference is that gasoline cars put a fuel air mixture in the cylinder then compress it and spark to ignite. In a diesel you first compress the cylinder then inject the fuel and allow it to spontaneously ignite, just what you don’t want in a gasoline engine.
’93 Volvo 240. 4 years to go to 20. I wouldn’t say no to a 940, but that opportunity came after I was broke from buying this
.
I shop wherever, depending on what I need (sometimes, the extra at the dealer isn’t so bad…sometimes, it’s insane). Advanced just got what I thought was going to be this week’s spending cash, earlier today, over three trips.
The first two here have pretty good prices (no idea if they’re decent; just from Googling). I have yet to see a cheap K&N for these cars. OTOH, even the dealer isn’t a real rip for filters and such, so there might just not be a need.
[www.performancecenter.com]
[www.autopartswarehouse.com]
[www.ipdusa.com] (I shop here, too, but they are pricey on some things)
…Premium fuel costs more and contains less energy densite. Who would be stupid enough to use it?
@Oshawapilot:
You don’t get it. The computer is not retarding the timing based on octane, the fuel is simply burning spontaneously before the spark plug fires and robbing you of the power and causing premature engine wear/failure.
This is supremely bad.
@stands2reason: Someone who likes performance out of his car more than an extra few dollars, like me.
While it has less energy “densite”, it does allow for a considerably higher compression ratio. My car is running well over 100hp per liter. “Regular” fuel would be considerably more expensive for me, because a) the engine would need to adjust and start working under suboptimal conditions, and b) I’d need a new engine if I decided to rev it up.
@gerardrj: Some computers can allow for suboptimal fuel by changing the injection.