According to many car manufacturers, Mechanics, and car technician have different theories about car maintenance. As many car websites and technician suggested to not to do what most car dealers do while regular car maintenance checkup, some of them are true and some of them are debate able.
I did a lot of research and gets as many as possible suggestion from Mechanics, dealers and experienced technicians regarding the typical most debated myths about car maintenance, here I will elaborate some of them for the users to clearly understand the car mechanics and what exactly a car wanted at the time of regular check.
I read most of the articles in which mostly all suggested about to changing the oil after 6000 miles or close to 7500 miles, to some extent it is true but not in all scenarios.
Oil interval time to change depend on Oil grades, Car model year, Weather condition, Engine health and Engine Color.
All these above factors must have to be consider before suggesting the time to change the oil, however the car manual also suggested as well but in general terms.

Oil filers comes in many varieties and qualities, it is very hard to judge which one is more good, therefore better to use moderate oil filter and change at every engine oil service.
A myths about to change the transmission oil after 40,000 to 50,000 miles, it is actually true unless a problem occurs such as leakage, Low quality oil used and many others. In addition regular checkup needed to check the oil viscosity and the level of the oil by simply open the engine hood and a separate gauge of transmission allocated to it.
Related Article: Common Automatic Transmission Problems and Symptoms
You don’t need to change the A/C and Air Filter in every oil change, Asked them to open it and simply clean them by using air pressure, good quality Filters can last up to more than 40,000 miles.
Those who used simple tap water for radiators must need to stop and used coolant to prevent erosion and blockage.to prevent all problems only used Coolant for radiators these coolants can last up to more than one year without any wastage.
A vehicle needs to replace a spark plug only when it crossed more than 40000 miles or the driver feel the car having a problem with Fuel efficiently, unstable Rpm and many others.
It will not true to say about that it doesn’t work, Injectors cleaners works to all cars but it provide results more on new engine cars than the old ones, therefore I would suggest to use injector cleaner instead of asking mechanic to open all injectors and clean it by using lubricants.
No need to go to workshop for every little problem occur in your car, you can check while at our home by using OBD system which works in most of the cars, these system can be able to identify issues and eliminate them if possible in fact it also saved a lot of bucks.
Related Article: OBD2 Diagnostic App or Car Sensor System Check (Android and IOS)
More pressure can save fuel and the tires lives longer but it reduces road grip and comfort, it up to you to decide what you want, In addition the recommended pressure would be best place on the door panel and in the owner manual book.
Use Tire Monitoring pressure system or gauge to check regularly about the correct Psi of your vehicle tires.
Related Article: Best Tire Pressure Monitor System Devices

As a general rule, you can use a higher octane fuel than recommended for your car. For example, you can use 95 or 98 in an engine designed for 91 RON, however you should not use the lower 91 RON petrol in engines designed for 95 or 98 as this can damage your engine.
Difference between 91 and 95 octane Fuel