Hello. I am going to purchase a 2011 XF with a normally-aspirated V8. The car has just over 300 miles on it, and is about 2000 miles from my home. I am considering traveling to the car with a friend and having us drive the car back home, instead of hiring a shipping company to do so. This would be for fun, and not necessarily to save money, because with gasoline and other expenses, I'd probably break even if lucky.

My question is how, or whether, I should break in the engine? Should I even do this trip? We'll drive about 36 hours straight through if possible. We'll possibly stop mid way for a rest of a few hours. My understanding is that it is not a good idea to go long distances with a steady throttle on a new engine. However, I don't know if that is mostly legend by now, or whether it applies to the 2011 XF's V8. Also, since the car already has about 300 miles, I don't know how much or whether that makes any difference.

Any advice would be much appreciated!

Sincerely,
Mark

 

I believe the break in period for modern cars is just myth at this point, id say go for it and congrats on the new car!

 

Just do whatever the manual says.

edit - If it already has 300 miles on it then it's probably through the "break in" period.

 

I think driving it back is fine. As you note, you should vary RPM somewhat and not just constantly keep it at a single RPM for the entire trip. It probably wouldn't make much difference if you kept it at a single RPM, but it's not hard to vary it. Just pull the paddle now and then to get into 5th.

 

Thank you for the advice, guys. You confirmed my suspicion that I shouldn't worry too much, but that varying the throttle is probably a good idea for awhile. It turns out that I won't be driving it from where I'm buying it, but your advice is useful in either case.

Mark

 

Just make sure that your buddy takes a fast car cuz he'll likely need it to keep up with you on the way back home!

Congrats on your selection. I've had mine for less than a month and I absolutely love it!

 

My salesman told me that they're good to go right off the showroom floor. They undergo break in at the factory on the bench.

Drive it!

 

I believe your salesman is wrong. As far as I know, Mercedes-Benz AMG and BMW M are the only mainstream car manufacturers that break in each engine before it leaves the factory.

 

Owner's handbook says to break in the engine for I believe 1000 miles. Also, the differential needs breaking in and I recall that takes longer, perhaps 1,800 miles. So, no hard cornering, no burning rubber starts and do not fully load the engine for more than brief bursts and never load the engine at high rpm until the mileage is accumulated. As for varying engine speed during break in that remains a good idea. If long highway mileage is involved the simplest way to achieve this is to manually downshift using the paddles periodically. The engine rpm will rise, load will drop and after 30 seconds the transmission will shift back into drive (assuming "sport" has not been selected"). Then,in addition, I would do the odd slow down and acceleration shifting down manually to get the rpm up which will do the trick nicely. Road and enforcement allowing one should stretch the engine to the limit as the break in is completed. My base model will do the limited 200 km/hr ( 120 mph) immediately after break in. Break in is just treating the car with respect while the parts all get used to each other. The engine rings need to seat and for that they need to go up and down the cylinder bores without overheating while the cylinder honing wears the rings perfectly into the bores. It is important not to baby the engine as much as it is to avoid abusing it during this process. A long highway trip is ideal if speed and load are varied.