Do I still need to run in a new car's engine?

I definitely would, just keep your speed under 55 or so for a few hundred miles if possible. This could also vary depending on what RPMs you’re engine runs for different speeds, respectively for different engine sizes. But honestly, most new cars as of currently are fairly solid, its definitely not a new technology, so if you don’t I’m not sure you’re really going to do much damage at all. I’m not a mechanic or engineer though, so if anyone does have more information than I please correct me.

yes, I’m sure it varies from one manufacturer to another but properly breaking in your new engine will help ensure its sustained life and overall reliability in the long run. Try and keep the rpms under 4k for the first 1200 miles or so. Also in this time period avoid full throttle, accelerate gently, don’t drive at speeds exceding 100 mph, and try not to drive at steady speeds for extended periods of time. Try to vary your speeds. This plus standard maintainence will help keep your vehicle in excellent mechanical condition for years and the repair bills to a minimum.

What @nivlac says is very old thinking, but I bet it’s 100% on the money! They (the) advertisments, say no break-in time required, however Click & Clack say yes. I would go with a real mechanic, not an advertising person.

definitely read your owner’s manual. It will give you the specific break-in schedule.

also VERY important to change your engine oil and oil filter at the lesser of 3000 miles or what your owner manual says for the first oil change. Breakin of a new or newly rebuilt engine will produce many minute metal particles that need to get out of the engine. most are caught in the oil filter but the breakin oil is especially highly populated with metal particles.

i wouldnt, but thats because my foot wieghs 3000 lbs, but to give advice you probably should becuase if your car is abused then it will void the warranty