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.
Method 3 Changing Your Engine Oil. 1. Know how often to change your oil. How often you need to change your oil depends on the type of car you own. Some cars need an oil change every 3,000 miles (4,800 km), while others can go up to 10,000 or even 15,000 miles (24,000 km) without an oil change.