Oil Change Every 3000 Miles?

     Transportation is so expensive these days that it pays to stay informed on the latest and greatest info, so you don't spend unnecessarily. I have come across many people that still think that oil needs to be changed every 3,000 miles to ensure engine longevity.The truth is that the 3,000 mile suggestion was issued back when internal combustion engine technology was still associated with carburetors and less advanced technology that employed in vehicles today.

     The introduction of fuel injection played a major role in increasing the efficiency of the engine (more complete combustion), which resulted in much less fuel remaining in the combustion chamber to leak past the piston rings into the crankcase. When unburned fuel seeps into the crankcase, it mixes with the oil and reduces its effectiveness, which does cause increased wear on the engine. Less fuel mixing in with engine oil results in longer oil life.

     Oil has additives such as detergents and anti-foaming agents which work to keep dirt suspended and prevent the oil from foaming as it's agitated in the engine. Many engine management systems in  late model vehicles are capable of letting the driver know when the oil is ready for being changed, but there are ways that you can tell for yourself.

• If the oil looks "dirty", it only means that the oil is working to suspend particles of dirt and that is what you want. Of course, freshly changed oil may not be visibly dirty, so this property doesn't tell you whether the oil needs changed, just that it's either working or it's new.
• After running the engine under load and at normal operating temperature, quickly check the engine oil dipstick and look for foaming (bubbles), which will quickly settle once load is removed. 
• Follow manufacturer's suggestion, which can often be found on a sticker in the engine compartment. I owned a 1986 Toyota Truck, which was one of the early fuel injection models and Toyota recommended an oil change at 10,000 miles under good conditions and 5,000 miles under harsh conditions. Good conditions for an engine are freeway miles in little variation in whether year around. Harsh conditions are those in which the vehicle is idling (running with no load) for extended periods of time like that you'd experience in city driving/stop & go traffic. 
• Some mechanical or electrical problems can cause an excess of fuel to enter into the combustion chamber, whether the engine is running or not and it may be enough to cause the oil to smell like gasoline. Oil typically has a consistent smell after it's been in an engine for a few hundred miles and anything apart from that could be cause for concern. A blown head gasket can also contaminate engine oil and make it appear foamy (often referred to as a milkshake-kind of appearance). 

     Just a little bit of knowledge could save you from having to skip that extra morning Mocha Latte

so you can afford to change your oil before it's due. You'll also be doing your part to reduce fossil fuel consumption.

Note: That used oil that must be taken to those free oil collection centers is often used as fuel in large ships out at sea. The ships aren't allowed to burn the oil too close to land, but far out at sea, anything flies.