Would The Prius Get Better Gas Mileage If It Weighed Less? Part1

Q: I have an idea for a story in your magazine. I was thinking you guys could buy a Prius and pull the batteries and anything at all related to the hybrid portion of the car. Obviously this adds up to a lot of weight—dead weight on the interstate where many people do most of their driving. No doubt this car would then get much better highway mileage. If they built it that way, it would be much cheaper and have a much smaller “carbon footprint” due to much less energy being used to build it. As the car is now, it often has to recharge the battery pack on the highway, hurting its real mileage, not to mention the burden of all that dead weight.

A: Your logic is faulty. Here’s why:

1. Overall weight has virtually no effect on steady-state cruising economy. Fuel consumption at expressway speeds on level ground is determined largely by aerodynamic drag and other parasitic drags such as the tire’s rolling resistance.

2. The onboard battery pack is charged, for the most part, when the vehicle slows down, capturing the energy that otherwise would be dissipated as heat in the brakes. It normally doesn’t get charged during steady-state driving or acceleration. (One exception: On some hybrids, notably Toyotas, the battery will be charged to load the engine when the engine is otherwise running to warm up or provide cabin heat. This avoids wasting the fuel needed to keep the engine running when the car isn’t moving. Clever.)

3. Aerodynamic drag goes up with the square of speed, but the power needed to overcome drag goes up with the cube of speed. It takes eight times as much power—or fuel—to go a constant 60 mph as it does to go 30 mph.

That’s why the Prius, the Insight and other hybrids can actually achieve better miles per gallon during moderatespeed urban stop-and-go driving than on long, high-speed freeway trips.

How To Fix a Car Paint Scratch

New Car + Parking Lot = Scratches and Chips

It's a fact of life. Other ­people often don't treat your car's paint with much consideration. Ditto for kids and pets, not to mention the odd troll with an attitude and a set of car keys. Respraying a car can cost thousands of dollars, while respraying a single panel may leave you with a clown car that doesn't match color left to right.

Fortunately, many small nicks, scratches and imperfections can be easily retouched. A careful job is unobtrusive and may well be almost totally invisible.

Proper conditions: Be comfortable

Before you break out your touchup tools, figure out what you're dealing with. If the scratch appears thin and white, it probably hasn't penetrated through the clear coat.

If it is body-colored or shows metal, you've got a deeper problem. Regardless, never try to touch up paint unless the temperature in your work area is shirt-sleeve- comfortable for you. The paint won't adhere, dry properly or gloss up. The ideal temperature would be in the 70s F, but 60 to 85 is acceptable. You'll need to be out of the wind and sun. Indoors is best, but a shady carport should do. The relative humidity should be less than 60 percent or so: The evaporating solvent will cool off the panel as it dries, potentially lowering the metal's temperature below the dew point and letting moisture ­condense on the surface. This is not ­conducive to good surface finish.

How To Unclog An Outboard Motor

Q: Six years ago I purchased a new 25 hp 4-stroke carbureted Mercury outboard motor. The carb is now suffering the effects of ethanol—a clogged fuel port stalls the engine at mid-throttle. I understand there are additives that will prevent or minimize this in the future, but is there anything on the market that will clean the carb out without having to dismantle it?

A: The only one I know of that claims to use enzymes to dissolve the organics left behind by ethanol is Starbrite’s Startron.

I’ve tried some in a generator that was left to bake for two years without fuel stabilizer. Just adding Startron wouldn’t get it started, but disassembling the carb showed why—the main jet was totally plugged, and had to be reamed out.

Because your outboard is still running, the additive might make is way in and dissolve the gunk.

On the other hand, I’m reluctant to tell you to do this and then have you stranded miles off shore when the carb plugs up completely. Got a second outboard motor on board?

How Your Headlights Work

Headlights have come long way since the crude lamps that lit the way for the first cars. Modern headlights use deceptively interesting tech to produce your car's beams, and the next generation—based on lightweight, energy-efficient LEDs—are on the way.

I'm willing to bet that drivers only think about headlights during one of two events: when for some reason they can't see at night, or when an oncoming car blinds them. Like the alternator, these critical pieces are overlooked—until they don't work. And that's a shame, because for the gearhead, there's a lot of interesting tech behind the glass. Like, for example, did you know that an HID headlight is like a lightning bolt in that a glowing arc of electricity illuminates the fixture? Plus, automakers are calling on headlights to increase not only safety but also fuel efficiency.

Knowing how your lights work will better prepare you to keep them maintained, so you're more likely to see that deer before it runs into your path. Besides, the rapid evolution of headlight tech is interesting in itself. Here's a primer.

The Old-Fashioned Way

The first cars used crude lamps fueled by either kerosene or (gasp) acetylene. About 100 years ago, the open flames were replaced with a small electric bulb housed between a polished reflector and a lens. These lights weren't sealed well, so the reflector corroded quickly, making the already insufficient lights even dimmer—and worse, they provided plenty of glare to oncoming traffic. These types of lights were made illegal in 1941, a scant year after the introduction of the sealed beam.

Sealed Beams

A sealed-beam headlamp is nothing different from a giant household bulb, a tungsten filament housed in a glass enclosure that's sealed and filled with inert gases. The reflector is inside the glass envelope. Like household bulbs, these gradually lose brightness as the tungsten evaporates from the filament and deposits on the reflector. Dippable high-and-low beams didn't come along until the '20s. Brightness and beam control in this era were inconsistent because of poor manufacturing tolerances. And the inside of the poorly sealed glass lens easily corroded, further reducing the brightness. Sealed-beam lights were cheap partly because they came in only three sizes—5- and 7-inch round and one square size—but more important, the standardized sizes limited styling differences among cars. Automakers started replacing sealed-beam lights with quartz-iodine technology in 1973.

Quartz-Iodine

Sylvania Silverstar H13 1. Quartz Glass 2. Support Strut 3. High Beam 4. Low Beam

QI is the predominant automotive lighting technology today. Legal in the U.S. since 1984, it uses a small bulb that resides inside a reflector/lens assembly. Thanks to modern sealing materials and techniques, the reflector is far less likely to corrode from moisture intrusion. The high-temperature quartz glass envelope allows the filament to remain at a much higher temperature, for a light that's closer to natural daylight. The higher temperature means a lot more light for the power consumed, but also makes the tungsten filament evaporate and redeposit on the glass, gradually reducing light output. To combat this, halogen bulbs are filled with iodine or bromine rather than the customary inert gas. The halogen combines with the tungsten vapor coating the cooler glass, then disassociates when it touches the hot filament, basically redepositing the evaporated tungsten back where it started.

Manufacturing these cylindrical bulbs is very high-tech. After the filaments are sealed to the glass at the bottom, most of the air is evacuated from the top. While a propane flame heats the neck in the top of the bulb to a semiliquid state, a jet of liquid nitrogen cools the base to minus 321 degrees F. Then a pellet of frozen gases is dropped in. Instantly, the hot, soft glass at the top is crimped, sealing the envelope. When the temperatures equalize and the gaseous pellet boils, the pressure inside rises to 4 to 5 atmospheres. The H13 high–low beam lamp shown in the lead photo is the industry's latest version. Computer vision systems carefully tweak the position of the filaments in each bulb as it's assembled, maintaining tolerances within 0.004 inch—which means replacing a lamp shouldn't require reaiming the headlamp. The high-beam filament sits at the precise focal point of the reflector, providing the best illumination up the road. The low-beam fila­ment sits slightly off the focal point to spread the beam and establish a cutoff pattern to keep glare out of oncoming drivers' eyes. Some quartz-lamp systems rely on the use of a metal shield to provide the cutoff pattern.

The color of bulbs is expressed as a function of the temperature of the light emitted. A QI bulb is around 3400 degrees K, as compared to natural sunlight, which is considered to be around 6000 K. Recently, we've started to see QI lights that have a blue-white color, not the usual warm yellow light. These are aftermarket bulbs with different filaments and glass coatings that attempt to emulate the blue hue of expensive high-intensity-discharge (HID) lights (I'll get to HID lights in a minute). While these bulbs do raise the color temperature, they don't get close to an HID's 5000-plus K color. Oh, and they don't necessarily raise the light output either. So what's the point? Style­—it's one way to spend $20 and acquire the cachet of $2000 HID lamps.

How to Break in a New Car

It’s a thing of beauty: A brand-new car, shiny and crisp. It makes you want to spend the whole evening walking around it. Pretty soon, the neighbors wander over to congratulate you—and to render advice.

Break it in carefully, one says: “No more than 30 miles per hour until it has 1000 miles on the odo.”

“No,” another says. “Drive it like you stole it, if you want it to be fast.”

Others recommend synthetic oil, or nitrogen in the tires, or a mouse-milk oil additive, guaranteed to double fuel economy.

The ritual of breaking in a new car is part of the body of knowledge we refer to as conventional wisdom. It’s not necessarily wise, and the technology of building a modern automobile has evolved to the point where a lot of “wisdom” is obsolete. Few cars specify a break-in procedure anymore, simply cautioning you to avoid extreme acceleration or extended idling for the first thousand miles or so, and there’s little in the way of extra service up front. Some don’t even mandate an oil change until 6000 miles. We think your new ride deserves better. Here are a few tips.

Engine Cylinder Walls

Piston rings don’t rely on their spring tension to seal against the cylinder bores. Instead, combustion gases work their way between the rings and the piston and force the rings outward. During the first few minutes of engine operation, it’s important that the throttle be opened pretty far at lower rpms to provide this high pressure. Otherwise, the rings won’t burnish the cylinder walls properly, and the engine will have high volumes of blow-by—which means excessive oil consumption and shortened engine life. If you’ve ever seen the car jockeys who drive new cars off the end of the production line into the storage lot, or the transporter drivers zipping up and down the car-hauler ramps, you’ll realize that this all-important step has been performed for you many times. If you’re installing a new engine, simply give it a few seconds of wide-open throttle in a high gear. For the first thousand miles, avoid constant speeds and throttle settings. If you commute in normal stop-and-go traffic, you’ll be fine. I advise against cruise-controlled sojourns across Nebraska.

Bearings

The admonition to keep engine revs low for an extended break-in period stems from the days when bearing and crankshaft manufacturing tolerances were far less rigorous and lubricating oil wasn’t nearly as good. While modern engines are assembled to much the same design clearances, the tolerances are much tighter, meaning the variability is smaller, greatly reducing the possibility of a tight spot. Redlining a fresh motor is generally a bad idea, but there’s no reason you shouldn’t drive normally. I would, however, avoid top-speed testing, drag racing or towing heavy trailers for the first 1000 miles.

Oil

I customarily change the oil in a new engine after about 20 miles, and again at 1000 or so. That 20-mile oil, you would think, would look pretty much like fresh oil right out of the bottle. Wrong. It usually looks more like metal-flake paint, iridescent with tiny particles of metal worn off rubbing surfaces inside the new engines. After a few hours of operation, this completely normal phenomenon slows down as the rings, camshaft, lifters and bearings burnish their respective mating surfaces.

Transmission

The engine break-in procedure also covers the gearbox and the clutch on manual-transmission cars. Most cars with automatic transmissions today are factory-filled with ATF and, supposedly, will never need changing. Some manufacturers are so confident of this that they don’t even have a dipstick or a fill hole. If the specified fluid is a more ­normal mineral oil, I’d change it and clean the pan after a thousand miles or so. The organic linings on the clutch packs shed a lot of debris, and it generally just turns into sludge that lies in the pan. You don’t want wear metals and sludge to get picked up by the pump and start circulating in the expensive bits.

(Photograph by Frederik Broden)

Brakes

New brake pads on new brake rotors don’t really require a break-in procedure. The texture deliberately left on the surface of the iron discs will grind down the fresh surface of the pad material within a few miles. Even so, refrain from high-speed stops or dragging the brakes for a few hundred miles. Racing pads, however, need to be heated up enough to fade and then carefully cooled off, which removes the top layer and provides better fade resistance.

Interior

Avoid the impulse to slather the interior trim with shiny protectants, which can leach the plasticizers out of new vinyl and increase the likelihood of age-related cracks. On the other hand, a generous dousing of Scotchgard on the cloth upholstery and carpets will keep dirt, pollen and mildew from clinging.

Paint

In years past, it was considered a good idea to not wax a fresh paint job for 90 days, to allow the paint to fully cure and any solvents to escape without being trapped under the wax. Modern catalyzed clear-coat paint is as hard as it will ever be as soon as it cures, before the car ever leaves the plant. Applying 3M Paint Protection Film to the leading edge of the painted bodywork will go a long way toward minimizing stone-chip damage. Otherwise, a good coat of wax will repel water, atmospheric pollutants and dead bugs.

NOW YOU KNOW: Is synthetic oil too slippery for proper break-in?

Conventional wisdom says that a new engine should be broken in on conventional mineral oil, regardless of your intentions to use a synthetic for the long haul. The conventionally wise say that synthetic oil is too slippery and won’t let the microscopic high points properly lap themselves in, delaying the break-in process. I say rubbish. Many modern cars, notably such high-performance marques as Porsche, Ferrari and Corvette, are factory-​filled with synthetics. You can bet that somebody has determined that the break-in process will proceed normally with synthetic in the sump of these ultra-high-performance engines. And that goes for your Toyota or Jeep as well.

Nonetheless, I do prefer to use a mineral oil for break-in. It’s $3 a quart versus $7, so I don’t mind changing it after 20 miles and again at 1000.

I would not, however, change the factory-fill synthetic back to mineral for break-in. Those vehicles typically have carefully assembled engines with instructions to do the first oil change at the regular interval, which could be up to 10,000 miles. In those cases, I simply change the oil early, before 1000 miles, just to be safe.

Synthetic oil is a superior product, particularly if your engine operates at the extreme ends of the temperature scale: high-temperature climates, towing or racing. But like any oil, synthetic will become contaminated with atmospheric dirt, wear particles, carbon, partially burned fuel, water and acid. Eventually, even if the oil itself is performing properly, all this extra junk will manifest itself as engine wear.

Also, the first oil change invariably reveals small particles of gasket sealer, chunks of unidentified plastic, the occasional metal flakes that weren’t cleaned off before assembly and even the odd washer or nut. It’s pretty scary. Better this junk come out sooner rather than later.