I know oil should be changed every 3000 or 6000 miles (depending on the car and conditions) but I'm not all that great at keeping track and I've let the car go for 10,000 miles before and it still runs fine (I know that's not "evidence" that I didn't do damage I'm just pointing it out). Most place put that sticker in the window but the sun in AZ usually makes those illegible or the peel off.
I know fresh oil is translucent and used oil is black but will it be translucent even after 2000 miles?
Find another way to keep track of your oil changes. For example:
put that window sticker in your glove box instead
if your driving patterns are consistent, figure out how long it will take you to drive 3000 miles and put a reminder in a Google Calendar.
put a notebook and pen in the glove box. When you change the oil, write it down, with date and mileage. Also, when you fill the gas, write down date, mileage, and how much - now you can see how your fuel efficiency changes over time. Put the service receipts in here, and it will help you sell the car one day.
change the oil every 3 months, regardless of mileage (not ideal, but better than forgetting it)
In addition to keeping the recommended oil change schedule, here's a quick-and-dirty way to evaluate oil quality.
Grab the dip stick and run it through your fingers to get them oily. Spread the oil on your fingers and observe:
Engines running on flexifuel/ethanol (aka E85) can preserve the oil longer due to cleaner combustion, and it would normally have lighter colour than a comparable gasoline engine at the same mileage after the last oil change.
To expand some on Jay's answer, which has good suggestions on how to remember to get the oil changed in a timely manner...
The oil gets pretty dark pretty quickly in a car. At 2,000 miles it's likely to look quite black, and I want to say that it's unlikely to be translucent at even 500 miles. Though it is usually somewhat different at 2,000 miles than at, say, 5,000 miles, it's really not a case where you can just look at the oil and it not being translucent indicates that you need to replace it...
I just look at the mileage on the car. If the mileage divided by 1000 is evenly divisible by 3, it's time for an oil change (quick math trick to make it easier, add up the digits representing thousands, ten thousands, and hundred thousands place, divide that by 3)... For example, my one car has 115,000 miles (7 divided by 3 = no oil change yet). The other has 249,500 (15/3 divides nice and evenly, and guess what, I just did the oil change 500 miles ago). :-)
One of my cars has clear looking oil for the first 1500 miles or so before it starts to turn dark. The other one starts turning dark within the first 100 miles. Oddly, the one that turns dark the fastest is the newer, lower mileage car...
Check your owners manual. If you don't have one, you can probably find a copy online. You may find that the suggested oil change interval is more than 3000 or 6000 miles - for my Volvo, for example, the recommendation is for 7500 miles (12000 km).
If you decide to use synthetic oils, the interval may be even higher. I know people have gone 20,000 miles between oil changes, and a guy named Doug Hillary did some testing to verify that the synthetic oil did not degrade over time (I believe the occasional top-up was enough to keep it within spec). But if you're concerned, you can always take a sample and send it in for testing.
Kilometers that can be driven on different base oils -Mineral based oils have a potential to last for any way between 3000-5000km, -Semi-synthetic can last for 7000-9000km, -Paraffin based and synthetic based oils can easily last for 15,000-20,000km
But this all depends on:- -The temperature of the country, -Kilometers covered in a stretch, -Driving conditions -The time for which your car is stagnant. -Engine capacity. This all is mentioned for cars.
And for visual checks -You should check the oil levels on the dip stick, -And as mentioned by 'mindcorrosive' the colored and the viscosity can tell you the condition of the oil. The darker and less viscous the oil gets you know its time to change.
Tips -Change the oil when the engine is a comparatively hot, helps to drain the oil easily but be careful not to damage the threading on the oil drain nut. -Change the oil filter with every oil change. -If metal filings are found in the oil you have a big problem, similarly if less oil is drained out.
Just for people like you (and me) there is a lubrication testing device:
A lot of short runs will degrade oil faster, but fully synthetic will be fine once a year. Even 12,000 miles is fine. Change it at the end of summer. People waste money changing their oil every 3000 miles/3 months. That's when the oil was not as good and they used to strip engines to decoke on dyno mineral oil without much detergents in?
While wiping the dipstick -hold the index finger/thumb together, slide stick out. Now seperate the thumb/index slowly apart. If the oil (visvosity) has broke down, it will seperate instantly-if its GOOD, there will be a thin film between the two when seperated 1/8-1/4inch.
I don't really go by the color of the oil. I do it on a 3 month schedule. At start of the year, just go through the calender and mark off a reminder around every 3 months. You should be able to find a holiday in most cases to help with reminding you. Been doing this for close to 20 years. If you have to use color to help you, then anything that has the color of molasses, it is time to do it now....not next month.
