Picking up my new MMH on Thursday and am looking for input on breaking in the new engine. The salesperson at the dealership told me use varying speeds for the first 500 miles.

Any thoughts and suggestions would be greatly appreciated.

Thank you

Break-in is generally referred to as the first 1000 to 3000 miles. Your owner's manual will have information on break-in, and the FEH manual does mention something about not driving at constant speeds for the first 1000 miles or so. I don't know if you've found the Mariner Hybrid owner's manual online, but the vehicle's are so similar you might enjoy perusing the '06 Ford Escape Hybrid owner's manual online.

I personally didn't do anything special in my Ford Escape Hybrid (purchased in March '06), and even took it on a all-highway road trip to Dallas and back home to San Antonio. On that road trip, I hit 1000 miles on the odometer at a stop light in Glen Rose, Texas, home of the famed dinosaur tracks... Glen Rose = Dinosaurs = Fossil Fuels. Fitting, no?

- Shannon (Geeky, Wild Texan)

Our Mariner just passed the 1,000 mile mark last week. Don't expect to get good mileage at all over the first 1,000. Maybe 27-28 MPG HWY and 25-26 MPG City. Personally, I believe that the system is programmed to prevent you from doing so during the break in period. I posted a thread about it in the forum not a week ago. Ever since the 1,000 mile mark, I have been getting much more out of battery mode including speeds in excess of 35mph. Don't expect to get over 25mph in battery mode no matter how hard (or soft) you try. Use the first 1,000 to learn how to drive the vehicle and use it to practice all of the tips on this board. Just don't bother looking at the "miles to empty", the MPG, or the trip odometer until at least 1,000 miles. Some say 3,000-5,000 miles is where you really start to see the improvement.

-Tim

2006 Mercury Mariner Hybrid AWD
Black with Pebble interior
Premium Package with Nav & Moonroof



Current ODO: 26,152
Typical Drive: 20 min crosstown in heavy traffic (3.5mi there and back twice a day)


532 Gallons of gas saved
That's 10,642 lbs less CO2 emitted

Hi Marc –

I did about the same with my ’05 FEH 4WD. We purchased it on a Thursday and that Saturday we left Atlanta to Williamsburg, Washington, New York City and back. Just about all expressway driving on cruise (65 – 75 miles per hour) and the FEH now has over 22K on it now, getting 32.1 MPG – without any problems.

I think the ‘Old School’, thinking with initial ‘Break-In’, and not holding a constant speed (RPM), has to do with getting even wear on all parts of the engine and drive train. In other words pressing on the gas puts pressure (wearing/smoothing down) say on one side of the cam, crankshaft, piston rings etc and letting off the gas has the same effect on the opposite side of all these components, therefore your entire system is balanced.

This theory doesn’t hold true for the FEH or MMH, so your salesman and the manual are wrong. The reason is because the PCM is constantly changing the RPMs to keep the speed constant going up and down hills even with the cruise control on - so you are getting that change of engine speeds without doing a thing. So I would say let her rip – not literally. I would keep the speeds down for the first 500 miles or so but after that - - - . Yes there is a Break-In of the total vehicle as far as getting everything 'losened up' so to speak. I guess it is just a case of all the parts having less friction etc and as far as I can tell - it just keeps getting better and better the more miles you put on it.

The 'Main' thing is - Enjoy - you have a wonderful machine.

I think the main thing that improves mileage is learning how to drive the hybrid efficiently. There is definitely an improvement that comes from the vehicle break-in but the driver break-in is important too.

When I got my '05, my first few tanks were right around 30 mpg. My first few tanks in the '06 average around 32 mpg (with the a/c on). There was a gradual increase in both of them as they got broken in but right off the lot I was able to match the mileage in the '06 to what it took me 3 months to do in the '05.

JMO of course but having broken in two of these, I definitely knew what I was doing the second time around.

I agree with you, Ray. I have an 04 HCH which helped me learn about hypermiling and hybrid driving (pretend you have an egg between your foot and the accelerator pedal). With that prior knowledge I was able to get 34-35 mpg right from the start in my FEH.

With a little over 2k on the odometer now I am averaging right around 35. In fact I looked at my gauge when I got to work this morning and show a 35.5 average with this tank (280 miles so far).