Saturday, August 4, 2012

Helpful Household Hints: The Car

This isn't the first time you've written about cars.

No.  But then I'm usually mulling on one make and model in particular.  Usually it's something that's near and dear to my own heart, or something that I consider noteworthy against the entire backdrop of cars.  The Toyota Corolla for example, venerable nameplate that it is, isn't really noteworthy for anything but being an efficient, compact family car.

So what's on the menu today?  The Fuller Dymaxion?

Not hardly.  But that's worth a look so by all means, click the link.  No, today is about your car.  The hoopy in the driveway.  Let's talk a little about that, and maybe a bit about the phrase "high performance."

My car's just a compact sedan.  No high performance in it.

Yes, there is.  There's the usual paradigm of high performance, making more power and going faster, which is fun in its own way.  Then there's taking what you've got, and making the most of what you have.

Chances are that, like most Americans, you aren't trying to race your car.  You just want to get there.  And you want to do it while spending no more money than necessary because, well, who has money to waste?  Not me, that's for sure.  So you're going to make your car do more than it usually does

Is this going to be about fuel efficiency?

Some of it, not all of it.  Some of it is just about making the car better.

First, an engine oil change is never a bad thing.  Oil is what keeps your engine from grinding itself to powder.  Under ideal conditions, there is virtually no actual metal-to-metal contact inside your entire engine wherever there are moving parts.  They should all be floating on a microscopically thin film of oil and in a well-cared for engine, that's actually pretty much the case.  But as oil ages in an engine, crud gets suspended in the oil and bridges the entire gap from one part to another, like a rock big enough to rest on the streambed and still poke out high enough for you to step on.  So change the oil and filter and get that gunk out of there on a regular basis.

I change mine every 3,000 to 5,000 miles.  You can go longer - no car manufacturer recommends an oil change interval that short, and in fact some Porsche models have 20,000-mile oil change intervals specified in the owner's manual.  But my paradigm is this:  cars are expensive.  Engines are expensive.  Oil isn't cheap either, but for the price of a new engine to replace the one you have, you can buy several hundred thousand miles' worth of oil changes.  So I'll go ahead and change the oil.

That's basic maintenance.  Anything earth-shattering in this post?

No.  Nothing earth-shattering.  Just record-breaking.

Keep your oil fresh.  Keep your tires aligned - that's important - and the excess weight aboard to a minimum.  Change the transmission fluid once in a blue moon while you're at it.  What about the lubricant in the final drive?  Many front-drive cars won't have this (it would be part of the transaxle), but if you're in a pickup truck, it's that big pumpkin back there between the rear wheels.  It has a quart or two of lubricant in there...unless you've never checked the level.  In which case you might be due for topping it up, or at least changing it with new.

You talk a good game, but can you offer any proof?

Yes.  I'm a member of, a fuel-efficiency enthusiasts' site.  Among other things, the site features the Garage, where you can record your vehicle's performance results as you adopt new driving styles and modify your vehicle for better performance.  With subtle changes in behavior, you can make your car deliver fuel mileage far in excess of what it's rated.  My truck is supposed to whistle up mileage in the 25-27mpg range; I've recorded mileage in excess of 39mpg on a couple of trips, and tend to average 30-33 without working hard at it.  You probably won't do as well as 33% above the EPA rating, but it isn't impossible either.  NOTE: my average is down lately because I drive the truck so little that fuel is evaporating out of the tank.  That's important to remember: fuel sitting around unused can actually just disappear.

What else can you do?  Now that you're making the most of an unmodified vehicle, let's think about modifying it.

Do you listen to the radio, or do you just have an MP3 player plugged in?  If you never tune the radio, take the antenna off.  That's a little frontal area removed, and some turbulent drag too.

That's pretty small change.  How sure are you that this will work?

I'm positive.  Every little bit helps.  The less drag there is, the less your engine has to do, and the less gas you have to burn to get around.  You have to change your driving behavior first so you aren't driving in a wasteful manner, and doing it consistently.  Once you've got that nailed, you can really start to see how all these changes add up.

Try replacing your existing wheel covers with ones that are smooth.  The wheels are big whirling air buckets; if you can cover the bucket, the whirling isn't as much of an issue.  It means you give up some style points, but if you're like most people, the car isn't for show.  It's just a tool to get you back and forth, and saving money counts for more than style.

If you drive a sedan, add a spoiler to the trunk lid.  This effectively makes the back of the car higher, and helps raise the trunk lid's edge into the smooth airflow zone tumbling off the back edge of the roof.  Hot VWs magazine discovered the classic "Herrod Helper" spoiler bumped up their mileage on their "mileage motor" project (getting a classic aircooled VW Beetle to deliver something close to 40mpg at 65mph like other modern cars) by 2mpg - nothing to sneeze at.  Not the silly wing style spoilers, just a little airdam lip poking up.  It makes a difference.  But to be sure, you have to test it with the spoiler on, then off, and compare results.  This requires some datalogging.  But if you aren't that meticulous or just don't feel like investing that much energy in it, a couple of coast-down tests can get the job done: find a spot where you can start at a known speed and let the car coast down, out of gear, to a slower known speed.  Whichever configuration takes you a longer distance before slowing to the lower speed is the better one.

Add wheel skirts.  At this point you have to get creative, because you can't just go and find wheel skirts to fit your car, not anymore.  You're going to have to make them.  Right now during election season there's lot of campaign signs around, and those things are made of Coroplast, which is the perfect material for making do-it-yourself wheel skirts.  Cut them to fit inside your wheel arches, and make them go as far down over the rear wheels as they will without rubbing.  If you don't want to screw them in, try sticking them on with 3M Command Strips or super-high-power rare earth magnets.

If I already have the smoothie wheel covers, do I need the wheel skirts?

Yes.  In fact you want both if you can have them.  The wheel covers reduce how much drag the wheel itself experiences - drag that your engine has to overcome.  The wheel skirts reduce how much drag the car's body generates, and that's another reduction.

The single biggest recommendation I have: slow down.  Nothing increases your fuel burn like driving fast.  The slower you go, the better, down to the limit where the automatic (if your car has one) will continue to hold highest gear and the torque converter locked.  If yours is a manual, your best mileage is probably right down there around idle speed, but that is generally not practical.  Most engines don't like that in any case.

Where are you going in such a rush?  Maybe if you left ten minutes earlier, you could cruise at a slower pace, arrive less stressed and having burned way less fuel per mile in the process.  Life doesn't have to be a constant hurry.  I've found that every car I've ever driven seemed to be especially happy right around 45mph, some of them seemed to barely even be running.  Don't try to comment saying that your car does better at thus-and-such a speed and does even better when it goes faster, because then you're asking me to disregard physics.  I'm too scientifically minded to disregard physics, especially for a hearsay report.

That's it.  Drive slower, do a little super-easy wrenching, save money.

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