Vendor 1 says it will cost you $50,000 and it will take 4 months, vendor 2 says it will cost you $100,000 and it will take 2 months, vendor 3 says it will cost you $60,000 and it will take 3 months. The average bid is $70,000, which what you put when estimating the cost of this task in your project budget. Vendor bid analysis can also be used to estimate the length of the task, by averaging all the durations submitted by the vendors in their bids. In the above example, the average length of the task is 3 months.
These days they both recommend every 5,000 miles and change the filter every time. And some people now say oil will last 10,000 miles, and we would protect the environment by not changing it as often. A 125cc bike engine works harder than a car. So I'd say changing it every 3000 miles might be justifiable.
Changing the oil isn't just a pesky chore--it's a necessity if you want your vehicle to last. Changing your oil with regularity can prolong the life of your engine and save you a lot of money and headaches over time. The bottom line: Buying oil is cheaper than replacing an engine. So how often should you change your oil? Knowing when to change your oil is tricky because there isn't a one-size-fits-all solution. Different cars and engines require different maintenance schedules. The old rule-of-thumb required that you change your oil between every 1,000 to 3,000 miles. This rule was black and white--about as basic as any rule of the road--and was drilled into drivers. But times have changed.