If you haven't been under the hood of a new car lately - or (just as important) read one of their owner's manuals - here are a few things to know that you might not yet know about but probably should:

* Don't use anti-seize compound on spark plug threads -


Well, check first to make sure it's ok to use anti-seize before you do. Some plugs don't need it. And you could regret having used it.


Anti-seize is a thread lubricant sold in little packets (or larger containers) at the auto parts store. Applied to the threads of a bolt or conventional spark plug prior to installation, it will help prevent the day-ruining sensation of that bolt or plug stripping the threads when you try to loosen/remove it down later on down the road. However, it may not be necessary to use anti-seize if the spark plug is plated (as many now are) and could cause other problems for you, such as inadvertently under (or over) tightening the spark plug, even if you're being smart and careful and using a torque wrench. See here for more detailed information.


* Diesel Don't Do's -


As the cost of gas has gone up, the popularity of diesel-powered cars has, too. There are more of them on the road today than ever before. Unfortunately - in many areas - there aren't that many diesel fuel fillin' stations. And some stations where diesel is sold haven't updated their pumps, which have super sized nozzles that fit big truck side-saddle tanks just fine - but won't fit into the female end of your car's filler pipe, leading to a god-awful mess if you try anyhow. It is possible to trickle the fuel in - if it's an emergency situation, your car is pretty much bone-dry and this is the only diesel fillin' station in sight. Just go slow - or it'll overflow - and backwash all over the place.


And: Be absolutely sure the diesel fuel is ultra-low sulfur (if your car is built to burn that). Use of "off-road" diesel will give your car's emissions system conniptions. Don't be tempted because it's cheaper. You'll end up paying a lot more.


* A larger tire is probably the ticket -


If you own an older car with 15 or (Motor Gods help you) 14 inch wheels, you probably have found out that your choices are pretty limited when it comes to tires. Currently, 16s are about small as it gets - with 17 and even 18 inch wheels rapidly becoming the de facto standard. What this means is that down the road, as fewer and fewer new cars come with "small" 16 inch wheels, the tire industry will offer fewer and fewer 16 inch tires. You might find yourself limited to one or two brands - and discover there's not much in the way of specialty compound tires, such as speed-rated/high-performance tires. This is a frustrating fact of life for owners of '60s and '70s-era muscle cars, none of which came with larger-than-15-inch wheels from the factory. Today, it is almost impossible to find modern performance tires for these cars. Their owners are stuck with basic all-season radials - and even these are limited in terms of brands/styles. So, if you're buying a new car - and plan to hold onto that new car - you might want to go with at least 17-inch-wheels . . . if you want to avoid scarcity issues with tires a decade or so from now.

* Don't touch that battery!


Some new cars (BMWs, for one) require a trip to the dealer to swap out the battery. If you pull the old, tired one yourself and replace it on your own - the car's computer may take affront. It might "spit a code" (the "service engine soon" light in the dash comes on - and stays on) or something more inconvenient. The car needs to be plugged into the dealership's computer - the BMW computer - to avoid such troubles. Of course, the downside there is having to pay the dealer to do what used to be - and arguably ought to still be - a basic, DIY task. In any event, read your owner's manual before disconnecting the battery - even if it's a dead battery.


* That ticking sound . . .

Speaking of diesels, they're no longer the only engines that "diesel." Many new cars with gas-burning engines also make that formerly diesel-engine-only signature rattling sound at idle. It's because of direct injection (DI) which is being adopted pretty much across the board in order to improve the fuel efficiency of gas-burning engines. DI differs from plain old fuel injection (FI) in that the fuel is shot directly into the cylinders under extremely high pressure (30,000-plus psi vs. 30-40 or so psi with plain old FI). Keep that pressure in mind. Never mess with the fuel lines if your car has DI - unless you're trained and equipped to do so. A fuel leak at 40 psi is bad news.
At 40,000 psi it is really bad news.


Throw it in the Woods?