It may not be necessary to change your vehicle’s oil and filter as often as you once did. Recommended service intervals have been increasing over the past few years from as often as once every 3-4 months and 3,000 miles to as infrequently as once every 5,000 (or even 10,000 miles), depending on the car – and how it’s used.
The reasons for the longer change-out intervals have to do with both improved engine designs – more efficient engines don’t produce as many combustion byproducts, such as unburned gasoline, that can contaminate the oil – and improved oil formulations and additive packages – which extend the useful life of the oil itself.
But there are several important things you should be aware of.
* First, remember that service recommendations vary from manufacturer to manufacture –
Don’t go by any “general rule of thumb” you’ve read about in the paper or heard someone say is ok. Go by the specific recommendations for your particular vehicle. See your owner’s manual – or ask the dealer.
* Second, keep in mind that service intervals generally fall into two categories: “normal” and “severe” use –
Don’t automatically assume your vehicle falls into the “normal” category – with longer service intervals – because you don’t drive fast or aggressively, etc. Everyday stop-and-go commuting is often considered “severe” driving, as far as the car companies are concerned. So is driving that involves very light use, such as short trips or very infrequent use of the vehicle. If the type of driving you do falls into the “severe” category, then you should abide by the service interval recommendations listed under “severe” use. They will likely be shorter than the intervals touted by the car manufacturer – which are based on their definition of “normal” use. Again, see your owner’s manual – or ask the dealer if you are unsure about which category your vehicle falls into.
* Third, be aware that all oils are not created equal –
High-performance synthetics, for example, can provide longer service (and superior engine protection, especially under severe conditions and loads) than conventional oil. And high-quality conventional oil will provide better (and longer-lasting) protection than lower-quality oil. The key thing is to always use oil – whether synthetic or conventional – that meets at least the minimum service recommendations specified by the vehicle manufacturer, including viscosity (such as 5W-30, etc.) and the specific American Petroleum Institute (API) classification for your vehicle. The API classification will be in the form of alpha-numeric ratings such as SJ, SL, SH, CH and so on. Your owner’s manual (or a sticker in the engine compartment) will spell out exactly which API service classification (and viscosity) oil you must use in your engine. It’s ok to use an oil that exceeds the specs (as with synthetics) but never use an oil that doesn’t at least meet the specs. Using oil that doesn’t meet the manufacturer’s minimum requirements can cause engine damage – and will void your warranty. The same goes for the filter. If you do your own service, be sure you keep receipts, noting the date and mileage at all changes. You may need to provide proof you serviced the vehicle properly in the event an oil-related engine problem crops up that involves a warranty claim.
Also: Don’t forget to periodically (at least every two weeks) check the oil level – or have it checked by your mechanic or someone you trust. All engines use some oil in the process of operation – and it’s important to make sure the oil level never gets too low. You don’t have to use the exact same brand/type of oil to top off – so long as it’s got the same API service rating (or better) than the oil you’ve been using. It’s also ok to use a different viscosity oil in a pinch to top off the level – for example, a quart of 10w-30 when you can’t find any 5W-15. But if you have to add more than a quart of thicker (higher viscosity number) oil to the engine, it’s a good idea to have a complete oil/filter change done as soon as you can. Modern engines with very close internal tolerances can be very sensitive to thicker oils and while you probably won’t do any damage by running thicker oil, it could lead to lower fuel economy and possibly problems with the emissions controls.