BUT THE OWNER'S MANUAL IS DIFFERENT-
We have provided a maintenance interval chart which is based on both the manufacturer's specific information and general industry standards. The time and mileage given should be sufficient to meet or beat the manufacturer's warranty requirements. If, for some reason, your owner's manual differs from this schedule, we would recommend that you follow the more conservative of the two in order to be sure that all maintenance occurs in a timely manner.
BUT THE REPLACEMENT PART IS DIFFERENT-
Another thing to remember is that maintenance intervals may vary with the type of replacement parts which are used. Spark plugs and synthetic oils are two good examples of this. Although we have suggested changing your oil and filter every 3,000 miles, use of a synthetic oil may allow you to lengthen or even double this mileage, IF your usage fits the proper patterns (highway miles, above freezing, with little stop-and-go and no excessive speeds... ). The recommendation we give for spark plugs is based on conventional plugs with an electronic ignition system, which probably covers most vehicles on the road. But, if you use special plugs, like the increasingly popular long-life Platinum plugs, you may easily be able to double the recommended replacement interval. The key here is to pay attention to the directions supplied with your replacement parts (and if you have never replaced an item before, check with the manufacturer for suggestions about original equipment).
IS MY DRIVING "NORMAL" or "SEVERE"-
Sometimes we are puzzled at how manufacturer's chose the term "Normal" for the style of driving which most refer to in their maintenance charts as the opposite of "Severe." Check your owner's manual and you will likely see that you are NOT normal. Sorry to be the one to tell you, but it's probably true.
You see, to be "Normal" according to most manufacturer's driving and maintenance recommendations you would have to: Drive the car for more than 10 miles or so (to make sure it properly warms up) almost every time you start it (never under freezing conditions, but not in excessive heat, dry or dusty conditions either). Most miles would have to be on the highway, NOT stop-and-go (few red lights or stop signs), with no excessive idling (in traffic or curbside), but NOT at excessive speeds. Well, some of you reading this will find that this applies...but most won't.
If ALL of these conditions apply, then most manufacturers call your driving style "Severe" and lump it in with trailer towing, racing, cab or delivery driving or even police or fire vehicle usage. The truth is that most usage probably falls somewhere in between. Actual severe usage, such as those that we have just listed, should require a LOT of attention to all of the various systems of a car (including early replacement of all fluids). But, the average person, who does not race or tow, will be fine with the 3,000 mile/3 month engine oil change and most of the other recommendations we have given. If you compare those recommendations with your manufacturer, you will probably find that they have listed those intervals for "SEVERE" usage and not "NORMAL." Maybe it is just a play on words. Just remember that it is your money (that you are driving around every day) and possibly even your life (kept safe by tires and brakes... ) so remember the general rule, maintenance is cheaper than repair. Don't be afraid of not being "Normal." Go ahead and admit that your driving is "Severe" and maintain your vehicle to match.
The charts we have included fall into two categories, Maintenance Schedule I (or what most manufacturers would call "SEVERE") and Maintenance Schedule II (what most manufacturers would call "NORMAL"). Schedule I should be followed if that vast majority of your usage is not comprised of highway miles in mild temperatures. Schedule I should also be followed if your truck is used in heavy traffic, frequent stop and go driving, carrying loads or towing, is exposed to excessive dusty or dirty conditions, or is operated in extreme low or high temperatures. As we explained earlier, we suspect most people should follow Schedule I.