1. every 3,000 miles
   every 5,000 miles
2. every 7,500 miles
   there's no consensus on this anymore

Want to start an argument among car buffs? Ask this question! Once upon a time, the 3,000-mile rule was golden, but newer cars don't need such frequent changes. However, if you drive a lot of short trips with stops and starts, or in inclement weather, you might need to change the oil more often. Every 5,000 miles might be a good choice.

1. five minutes
   fifteen minutes
2. however long it takes to completely warm up the engine
   this should be done cold

The best time to check the oil level is before the car's first start-up of the day. That'll give you the most accurate reading on the dipstick.

1. five minutes
   fifteen minutes
2. however long it takes to get the engine and oil fully warmed up
   oil changes should be done cold as well

Five minutes is enough to circulate the oil and thin it out. Any longer, and you risk burning your hands on hot oil and/or engine parts.

1. jack
   jack stands
2. drop light
   timing light

If you said "jack stands," go to your room! One of the most dangerous things you can do as a shade-tree mechanic is go under the car using only a jack. Always use jack stands as well.

1. your timing belt taut
   your gas tank topped up
2. your tires well-inflated
   a crucifix hanging from the rearview mirror

Don't laugh at that person at the gas station who's always crouched by the air hose, trying to keep his or her clothes clean while adding air to the tires. It really helps with mileage, as well as acceleration when you need to pass. Just don't overdo it -- over-inflated tires can make for a rough ride.

1. silly putty
   a nail file
2. a penny
   a sewing needle

Here's the penny trick: Slip a penny into the tread with Abe Lincoln's head upside down (going in first). In a fresh new tire, his head should disappear. If you can see his whole head, it's time to replace your tire.

1. two minutes
   three minutes
2. five minutes
   it depends on your car's year

Today's cars don't need to idle for minutes after the first start-up of the day. This was common practice back in the day, but no longer -- and it just wastes gas and hurts air quality.

1. changing a tire
   replacing an air filter
2. replacing an oil filter
   rebuilding a carburetor

This wrench is for the big lug nuts on the wheel. Don't forget to loosen and tighten them in the right order -- opposite-to-opposite, not going around the wheel in a circle.

1. yes
2. no

Here's the skinny from the Car Talk guys, Tom and Ray Magliozzi: "It's true that premium gasoline does contain special or extra detergents, but in our opinion they're of no added benefit." Neither does it give you better mileage. Ignore the sales pitch, even if your dealer's warranty specifies using premium gas in your new ride.

1. a broken timing belt
   a blown fuel-pump fuse
2. an overheated radiator
   both #1 and #2

An overheated radiator is a problem, but it's a problem that gives you time to find a freeway exit, maybe even get to a service station. When the timing belt snaps or the fuel pump fuse blows, it's lights out, right away.

1. brake lines
   carburetor
2. spark plugs
   starter motor

Fuel-injection systems replaced carburetors, starting in the 1980s. Carburetors are easier to work on at home -- some skilled mechanics even like to rebuild them.

1. at the back of the glove box
   right next to the battery
2. in the trunk
   under the dashboard

It's useful to locate this before you need it; it's not usually difficult to reach. Then carry some spare fuses in the glove box, so you'll have them when you need them.

1. changing the oil
   changing the coolant
2. replacing spark plugs
   a ring job

If your piston rings are loose, you're losing compression and need a "ring job." This requires disassembly of the engine and is not to be undertaken lightly. Happily, it's usually a problem for older cars only.

1. brake job
   dipstick job
2. transmission job
   valve job

A valve job means cleaning carbon deposits off the valves to improve compression. It is difficult and time-consuming, and fortunately, with better-made engines, it isn't often needed in newer cars.

1. the accessory belt
   a poor grade of gasoline
2. inadequate tire pressure
   the starter motor

Why should a belt affect the cooling system? According to car expert Deanna Sclar, this is because the accessory belt drives the water pump. Ah... all is becoming clear! This is one of several issues that can cause overheating.

1. adequate engine oil reduces waste heat
   oil is inherently low-temperature
2. the cooling system is powered by engine oil
   it doesn't

As with the other tip on overheating, this one comes from Deanna Sclar. It's one of several reasons to keep a close eye on the level and the cleanliness of your car's oil.

1. a dipstick
   a funnel
2. a hex wrench
   a timing light

You'll use a funnel to add oil, but not to check it. To do that, you'll just need a clean rag and knowledge of where to find the handle of the dipstick.

1. lighter
   heavier
2. more
   modern cars do not need different weights of oil

In years past, people would put a lighter-weight oil in their car during the cold winter months, to keep it circulating freely, and a heavier weight in the summer. Not anymore; engines are much improved since then. Use the oil your owner's manual recommends, year-round.

1. true
2. false

If there is an automaker that also produces its own engine oil, we can't think who it is! The big carmakers are simply re-branding engine oil with their own name. Save some money and go to a regular auto parts store instead.

1. 5,000 miles
   10,000 miles
2. 20,000 miles
   six months, regardless of miles

Though the idea of a car that runs on air sounds like the stuff of urban legend, it's kind of true! Your car doesn't just run on gas, but on a fuel-air mixture that explodes in the cylinder. So changing the air filter is important. Fortunately, the filters last much longer than engine oil.

1. a 100-mile trip on the highway, at about 65 mph
2. 100 miles of town driving at 25-30 mph

The disconnect here is tha we tend to think of our cars as like our bodies: it'd be much, much easier to jog 5 miles at a medium pace on 20 different days than to run 100 miles at once at a high speed! But cars aren't like bodies; once machines start running, they like to keep running. Stops and starts are actually harder on your car than consistent operation at freeway speed. This is why you might need to change oil more often if you do a lot of town driving.

1. during a lightning storm
   in very cold weather
2. when on an extended vacation
   when driving through deep standing water

If you're storing your car or going on a long trip, disconnecting the battery will keep various devices (onboard computer, etc) from slow draining it. (And yes, the fourth option is a joke -- we know you can't drive with a disconnected battery!)

1. one
   two
2. three
   a hybrid car doesn't use a battery

A hybrid car has a regular battery of the kind you can pick up at Pep Boys. But it also has the hybrid battery, which is much more complex and expensive to replace. If you need to store your hybrid car, talk to a qualified mechanic about how to disconnect the hybrid battery so it doesn't die.

1. drink a cup of coffee
   smoke a cigarette
2. actually, you shouldn't smoke ever
   Ma? Is that you?!

Obviously, a lit cigarette is dangerous in a garage. A cup of coffee and/or a sandwich are actually important accessories to lengthy engine work. That is, if you find yourself getting frustrated with a job that's not going well, take a break before you skin your knuckles, break off a spark plug or something similar.

1. baking soda
   petroleum jelly
2. an old toothbrush
   pipe-stem cleaners

Corrosion tends to build up on car batteries. Remove it by disconnecting the cables and scrubbing them gently with baking soda on a damp toothbrush. A coating of petroleum jelly finishes the job.

1. the positive
   the negative
2. it doesn't matter

If you have a background in finance, don't get confused here. With car batteries, red marks the positive cable/terminal and black the negative -- the opposite of the financial world, where red means debt and being "in the black" means you're on the positive side of the ledger.

1. water and coolant
   green and orange coolant
2. different weights of engine oil
   different brands of engine oil

Technically, these are called ethylene gycol (green) and Dexcool (orange). Mixed together, they will thicken and clog up engine parts -- so don't do it. On the other hand, diluting with water is safe; in fact, with some coolants it's necessary.

1. on the gas pedal
   on the starter motor
2. in the cooling system
   on a carburetor

The idle speed screw, as the name suggests, adjusts the speed (okay, RPMs) at which the engine idles. So if your older car is idling high and wasting gas, tighten up the screw and fix the problem.

1. low-quality fuel
   poor-quality spark plugs
2. a battery issue
   poor gas mileage

If your headlights seem underpowered, don't replace them until you've cleaned the battery terminals and checked the cables for fraying and wear. If that's not the problem, a new battery altogether might take care of the problem.

1. just after being replaced
   very hot days
2. on trips under five miles
   on a cold night when you left your cell phone at home

It's easy to relax after you've replaced a belt: "I won't have to worry about that for a while!" But a new belt, put on too tight, can easily snap. Check it after driving a few miles, and make sure there's a little bit of give (no more than a half inch). This can save you a breakdown.

1. a hammer
   slip-joint pliers
2. a socket wrench
   all of these might be used

If this answer surprised you, it was because of the hammer, right? Okay, a hammer isn't an everyday tool in car repair, but "percussion" with a ball-peen hammer actually does loosen up tough nuts and bolts. Just don't go crazy with it.

1. the oil dipstick
   the fan
2. the idle speed screw
   spark plugs

Spark plugs are notorious for settling into the engine and never, ever wanting to leave. Don't feel like a failure if you have to have your spark plugs replaced by a professional mechanic.

1. yes
2. no

This is true of most cars, though if you have a very recent and high-tech model, you might want to check your owner's manual. For everyday use, coolant is better, because it doubles as antifreeze.

1. coolant
   gasoline
2. motor oil
   windshield-wiper fluid

Like motor oil, coolant is toxic and should be recycled. But its appeal to cats and dogs is an extra reason that you shouldn't let any spill on the ground.

1. of course!
2. no, not really

Okay, you could strain to find ways that cleanliness leads to better function -- like if rust got so out of hand it affected the engine or power train. But generally, the correlation between clean cars and healthy ones isn't causative. It's just that people who like to spend time keeping the engine purring tend to want their ride to look its best, too.