Is it true that old engine oil uses more fuel? car use less fuel with less oil? use less fuel in winter?

ok here is 3 questions! please tell me which statement is true?





1. i change oil every 5000kms, people say that when engine oil gets dark, old, ur car will use slightly more fuel, is that true?





2. people also tells me ur engine will use less fuel if ur oil level is closer to the lower end of the dip-stick





3. people also say that in winter cars use less fuel than in summer(not because air-cond)Is it true that old engine oil uses more fuel? car use less fuel with less oil? use less fuel in winter?
1. Every 5,000km, or 3,000 miles is good. Conventional oil you have ot change it at that interval...The industry standard is now full synthetic oil, which i use. You can aactuallygo 5,000 to 7,000 miles. And considering its double the price you aren't losing anything. You gain performance, better engine protection, and long maintenance intervals. I prefer Mobil 1.





Something to realize when your oil is dirty. Over the time of the oil's life in the engine, gas will penetrate the rings and other parts to make its way into the oil...Gas is a cleaner, and of course will reduce the oil's protection properties. Plus, you can have metal, sludge, and other particles in the oil, but tthat's what the filters for. Still, that's why you must change it regularly.





2. That makes no sense...Always run the maximum amount of oil that your engine should have.





3. That is a myth, and frankly a stupid one. Just like number two it makes no sense. First, the engine takes longer to warm up. Which means until it hit the optimum running temperature its running in a less efficient manner. Second, everything run slower in the winter. Ever notice how your hands get stiff when cold? Think about all the grease in the bearings, tranny, etc. These components are made to run at warm temperatures. And like the engine, until warm they are going to have more drag.








Hope that helps.Is it true that old engine oil uses more fuel? car use less fuel with less oil? use less fuel in winter?
1. Yes, to a point. As oil wears, it goes thin, then gets thick. The longer your oil is being used, the thicker it gets due to collecting varnish, soot, carbon, etc. But, you won't notice this at 5000km, more like 20,000 km.





2. Less oil means less frictional loss which might offer more efficiency, but again, a little bit will not make a noticeable difference. In real world driving, the down side to less oil is a hotter running engine and less protection. Its like stepping over a dollar to pick up a penny.





3. Hmm... my experience is different. Cold engines are not efficient. Engines like to be hot to provide the most power and efficiency. Also, winter fuel is blended to work better in cold temps, but it puts out less energy and causes worse gas mileage. So I will say #3 is wrong.
1 yes as there is more junk in the oil and the thing is clean oil would be more slippery and have less friction than dirty oil.


2 not true at all.


3 cold winter air is thicker than hot summer air and therefore provides more volume in the combustion chamber and a better economy than hot air.

red hair