Top speed during break in?

[Kwilli]

I was wondering if there were restrictions during the break in period of my new 2013 FFH titanium?? I read the manual and remember it saying something about not going "overly fast"? Is there some sort of hard number, like don't go over 75 mph??? Thanks for any advice

[GrySql]

The gas motors are run and tested before install so the old 'break-in' procedures are a somewhat grey area.

Some of these FFH's do have a tendency to get a little better mpg's after the 4,000 mile mark, more or less.

With all the gadgets and accessories the FFH's have just driving can get distracting, so until you really get the feel of the car I would not push things, speed-wise.

For better fuel economy and a happier drive my vote is to stick with the speed limits in your area - these cars are very relaxing to travel in.

Edited April 24, 2013 by GrySql

[acdii]

Just vary the speeds for the first 1k miles, dont hold a steady constant speed during that time, and that is all. Keep it under 100.

[neod192]

Keep it under 100.

That shouldn't be hard .. considering the top speed is 120 :)

[GrySql]

That shouldn't be hard .. considering the top speed is 120 :)

I read somewhere that the FFH's computer cut-off is set to a max of 108mph.

[neod192]

I read somewhere that the FFH's computer cut-off is set to a max of 108mph.

Yuck! I'll miss going 125-130 then!

[acdii]

Well, you can always ride in the back of my Flex! Pretty sure I can get it to 140 once I disable the cutoffs.

[GrySql]

Pretty sure I can get it to 140 once I disable the cutoffs.

Does the Flex have a McHenry County sheriff detector built in?

[acdii]

Yeah, its called driving in Boone County! LOL

[Kwilli]

Thanks for the help and replies!!!

[milleron]

The admonition against driving at a steady speed for the first 1,000 miles is age-old . . . like me. I've tried to follow this fuzzy rule ever since my first new car in 1976 without understanding the intricacies of it. I wonder if anyone does.

• Why is this important?
• How long can one remain at a steady speed during the break-in period?? Should one avoid using the cruise control altogether? Is it so important that heavy freeway traffic, that more or less dictates a steady speed, should be avoided?

My dealer says they expect delivery of my car today, so I'd like to understand this better. I'm pretty sure it won't, in fact, happen today, but just in case . . . .

Edited April 25, 2013 by milleron

[acdii]

The engine needs to vary its speed for proper break in. If it turns at a fixed speed it will develop a wear pattern that can cause it to not seat the rings properly, and start to burn oil. The only thing that really gets broken in are the piston rings, and valve guides. The bearings have that thin film of oil that prevents wear, so no wear develops there. Varying the speed changes how the rings move in the cylinder walls. Mainly break in is to seal the cylinders properly for a long life. On the Hybrids though, as things move over time, they loosen up and move freer, and along with tire wear, you will see a slight increase after 10-15K miles, then when you replace the tires, you will see a slight decrease until they wear in.

 

Hope that helps explain it.

[milleron]

The engine needs to vary its speed for proper break in. If it turns at a fixed speed it will develop a wear pattern that can cause it to not seat the rings properly, and start to burn oil. The only thing that really gets broken in are the piston rings, and valve guides. The bearings have that thin film of oil that prevents wear, so no wear develops there. Varying the speed changes how the rings move in the cylinder walls. Mainly break in is to seal the cylinders properly for a long life. On the Hybrids though, as things move over time, they loosen up and move freer, and along with tire wear, you will see a slight increase after 10-15K miles, then when you replace the tires, you will see a slight decrease until they wear in.

 

Hope that helps explain it.

 

Well, that addresses the theoretical question, #1. I still don't understand, though. No matter how fast the pistons and valves travel, they still do one complete stroke cycle per revolution, so I don't understand where the "wear pattern" comes from, at least as far as piston rings are concerned.

 

However, it's not important for me to understand that. What I would really like answered is my question #2.

 

Does anyone know the practical details of how to manage speed during that first 1,000 miles? "Avoid constant speed" is just too vague. I'll do anything necessary to break in the engine properly, but I don't want to spend the first 1K miles changing speed ceaselessly if that's not truly required.

[acdii]

Oh thats easy, just dont drive 65 MPH, instead drive, 55-70-60-65-70. Vary your speeds on the highway. Same in city driving, dont hold a constant steady speed for any long period of time. If you take a 500 mile trip and set the cruise to 70, thats is what they dont want you to do. Vary it instead.

 

However, in the Hybrids, the constant speed thing isnt as important since it uses a CVT which already varies the engine speeds. The thing is though, break in takes longer since the engine doesnt run all the time.

 

As far as piston travel, they may be going up and down, but there is also some side play involved from the forces of the expanding gas. When under hard acceleration, the explosions are more intense and force the piston in a direction opposite of the point of ignition. In some engines, the spark plug is off to the side, so the bottom of the piston is forced to the opposite side of the cylinder, but at a steady rate of fire, like when cruising, the piston is centered in the bore. When you decelerate, the piston can move to the opposite wall. In center fire engines, which I do believe these engines are, the force of the explosion is dead center on the piston, so there is very little side play involved, The rings seal the cylinders, and the pistons float inside them and ride on the rings. When you wear in the rings properly you get a good seal that lasts a long time. If you constantly hammer on the engine during break in, you can offset a ring or too, or worse, break one, and the engine will start to burn oil long before anything else wears on it.

[murphy]

The problem with this is that you have no control over engine speed.

The computer sets the engine speed and transmission ratio to what the guy that programmed it felt was best. They could have very easily set the computer to break in the engine with no assistance from the driver. I'm sure they didn't because it would have been an interesting marketing point.

 

Put the tach in your instrument display. It's interesting to accelerate from 35 to 40 and see the engine RPM be the same at both speeds.

That was on the 2010 that I traded in on an Energi. 99% of the time the engine isn't running in the Energi. My local destinations are 21 miles or less round trip.

[hybridbear]

I believe the owners manual says not to maintain the same speed for more than 1 hour during break in period

[acdii]

It's something like that. This is part of the reason that Ford can't make up their mind on the true break in period. Everyones drive will vary, and since there is more time when the ICE is not running, that just means it takes longer to meld all its parts.

[Kwilli]

This is all great information, I'm taking a small trip this weekend. 6 hours round trip all major highways, so I plan to vary my speed throughout the trip! In my normal day to day driving my speed varies greatly.

 

I was mainly worried about 1) going to fast 2) to heavy acceleration and 3) how variable did it need to be.

[acdii]

I wouldnt worry too much about it with the Hybrid. Try keeping it below 75 for the first few hundred miles, after that, just drive it.