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How do I maximize Highway MPG?


Mitchvino
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:congrats: and welcome Mitchvino.  At 65 MPH I would suggest using ECO Cruise and letting the car dictate modes.  It is very tough to out-smart the car (engineers at Ford) at highway/freeway speeds.  (There are some down-and-dirty mods to the grill area (plumbing pipe foam raps etc....) you could try since it is winter to keep the ICE warmer.  Look up grill covers & or winter driving tips)

 

Enjoy,

 

Nick

 

ICE - Internal Combustion Engine

Edited by C-MaxSea
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#1.  Adjust the air pressure in your tires. These tires are rated to 51 PSI.  Check them every month.

#2. Don't haul unnecessary loads,

#3 Take yourself out of the rat race and drive the speed limits.

#4 Do a search for grill blocks.

#5 Use the DHA when driving in areas with hills. Don't leave it on when driving on flat roads.

#6 Use synthetic oil. 0W20.

#7 Learn how to shut the ICE off when you're reaching the top of a hill and run in EV sooner

than the CC will kick it off. The car will run in EV up to 85 MPH. Take full advantage.

 

#8 Enjoy the learning curve and video game ;)

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Short answer: Set ECO cruise and enjoy the ride.  If its hilly and traffic is heavy I often switch ECO mode off so as to maintain a more steady speed.
 

One More Tip:  Use ethanol-free gas if you can.  Better mileage and no alcohol in the engine.  You have to decide for yourself if its "worth it".

 

Concerns:
 - If you raise pressure, make sure your tires are actually rated for it.  Michelin makes two nearly identical tires but one is only rated to, I think, 44 psi.  Haven't heard that any are on the C-Max but I would check your own tires.
 - Synthetic oil I use, but I'm concerned about "thinner" 0W-20 from standpoint of wear.  No doubt there's some debate on this issue.

 - I wouldn't use DHA engine braking unless it was was a really long hill, the HV battery filled up and I didn't want to brake.  I wouldn't have it ON just because the road wasn't flat.  I don't understand how it saves gas.  It just moves wear from the brakes to the engine.  In fact, if the HV battery isn't full, DHA would waste gas because it dumps energy into the engine and exhaust instead of the battery.

 

All said, have a great trip!

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Brand new owner here looking to take a 300 mile round trip on the highway.

Any suggestions for maximizing MPG @ 65 mph?

Thx

Being a New CMAX Owner you may not be ready for Hypermiling techniques, but this will give you an idea what can be done. If you're driving the car yourself taking advantage of terrain will reward you around 2mpg over ECOcruise but it does require some effort. Here is an example of 500mi. leg on trip across the country. This is a Post from a different thread.

 

OK, so I did it on my 5K trip to San Diego and back.  I did it between Flagstaff,AZ and Amarillo,TX with two stops in Gallup,NM and Albuquerque,NM and made the 500mi. around San Juan,NM. I have New Michelin's on the car and Odometer is off by 1.019% according to Garmin GPS. Actual numbers are for mileage(512mi), speed(66MPH) and 47.1mpg for the whole tank and looks like 47.3mpg for 500mi.

 

Here is how I did it, I used a banking system where I would save MPH and MPG.  So if MPH got low I would trade MPG for MPH.  I used Garmin to track MPH average and Smart Gauge to track MPG average. I took I-40 all the way to Memphis,TN.  The elevation drop from Flagstaff to San Juan is about 3,000Ft, but there are three over 7K ft. summits  between the two city's.  Starting about 2PM in the afternoon from Flag with the plan that I should be able to bank both MPG's and MPH's going down to Winslow(50mi. and 2K ft drop), but things went  BAD quickly with two different problems.  Rain and Semi's, as it turns out it rained at least 1/3rd of my trip and had to deal with alot of Semi's, easily half of the traffic on I-40.  Rain hurts both MPG's and MPH's and you can't draft Semi's in the rain if you want to see where you are going.  On the other hand being forced to follow Semi's while they are passing each other helps MPG's but kills MPH's.  So By the time I got to Winslow things where looking BAD, instead of having alot of extra MPG's and MPH's  banked,  I was already short with 45mpg, 67mph, I almost gave up not seeing how I could make up the deficit.  Then things started to improve, the rain stopped and I was able to start passing Semi's and get some drafting help while I was waiting to get around them. Then about 40mi. later the winds changed from cross wind to tail wind so then the numbers were getting better.

 

I stopped in Gallup, NM with about 67.5mph and 47.5mpg, but with stopping and getting going again I lost 1 mph on the Garmin, worse on Smart Gauge.  OUCH! Then I hit rain again and winds stopped, still I was ahead of the game when I got to Albuquerque. Lost .5mph for that stop and hit rain again, but not to bad. Eventually I just kept MPH average at 66 and aloud MPG's to slowly climb knowing Smart Gauge would be optimistic by a couple of MPG's.  Most of the time I was going 69-70mph when I wasn't stuck behind Semi's or in construction zones. You may have noticed my top speed on the Garmin was 81.3mph! This exercise shows that 500mi. is a long way to go without having weather and traffic problems. When conditions are favorable, my CMAX will get 47mpg at 70mph. :)   Paul     

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Edited by ptjones
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I forgot some more tips for good CMax Mileage:

 

1.  Don't drive when it's hot, AC will knock off a few miles a gallon.

 

2. Don't drive when it's cold, heater and cold starts will knock off a few miles a gallon.

 

3. Don't drive when it's raining, wet roads will knock off a few miles a gallon.

 

4. Don't take anyone with you or carry luggage.  Extra weight will knock off a few miles a gallon.

 

5. Pump up one tire until it blows off the rim. Replace it, then run all your tires at 2 psi below the blowoff pressure.  Ride will be horrible, but you may get better mileage.

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Cold and rain are killers for sure, and A/C too if you don't manage it.  Use recirculation, close unused vents, turn up the fan and set temperature as high as you can (I use about 76F).   Set MyView to show Accessory power and you'll be amazed.  With above settings I can get it down around 300 watts (about a 1 mpg loss).  Crank it wide open and it goes to 10X that.

 

Weight is a factor but not that big a deal when cruising.  Say you add 200 pounds (about 5% of car's weight).  At 65, rolling resistance is maybe 1/3 of total drag at the most.  So the net effect is about 0.05 * 0.333 * 45mpg = 0.75mpg.  Less than 1 mpg!

 

When the fully autonomous C-Max comes out we'll be able to run it about with no passengers and get even better mileage!  It can go real slow with no A/C or heat needed! :lol:

Edited by SnowStorm
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Short answer: Set ECO cruise and enjoy the ride.  If its hilly and traffic is heavy I often switch ECO mode off so as to maintain a more steady speed.

 

One More Tip:  Use ethanol-free gas if you can.  Better mileage and no alcohol in the engine.  You have to decide for yourself if its "worth it".

 

Concerns:

 - If you raise pressure, make sure your tires are actually rated for it.  Michelin makes two nearly identical tires but one is only rated to, I think, 44 psi.  Haven't heard that any are on the C-Max but I would check your own tires.

 - Synthetic oil I use, but I'm concerned about "thinner" 0W-20 from standpoint of wear.  No doubt there's some debate on this issue.

 - I wouldn't use DHA engine braking unless it was was a really long hill, the HV battery filled up and I didn't want to brake.  I wouldn't have it ON just because the road wasn't flat.  I don't understand how it saves gas.  It just moves wear from the brakes to the engine.  In fact, if the HV battery isn't full, DHA would waste gas because it dumps energy into the engine and exhaust instead of the battery.

 

All said, have a great trip!

 

DHA only use the ICE, if, the HVB is full. Otherwise, it regens otherwise lost energy when driving downhill.

I use it in combination with the ECO Cruise to keep a steady speed on the backroads. We have lots of hills :shift:

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DHA only use the ICE, if, the HVB is full. Otherwise, it regens otherwise lost energy when driving downhill.

I use it in combination with the ECO Cruise to keep a steady speed on the backroads. We have lots of hills :shift:

Are you referring to 'L' position or using the button on left side of shifter knob?  I tried 'L' once coming off a mountain after HVB was full.  It worked alright but at the bottom the ICE wouldn't shut off - not even after coming to a complete stop!  Crazy - it just kept running.  I think it kept running in Park!  I've used the button but there was sometimes a jerk when the ICE would cut back off.  Is that normal?  I'm a bit uneasy about the whole thing - high RPMs and jerking.  It does really work though.

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I would not block the intake on the CMAX on the highway (or anytime for that matter) Your CMAX will reach operating temperature really quickly on the highway. Let's just say less than 1% of your driving on a full tank spent on the Interstate is at less than operating temp. You are risking engine damage to help control heat for only 1% of the drive--completely pointless IMO.

 

Keep the tires inflated, but know if you exceed the recommended pressure too much it will cause premature tire wear and it reduces traction (especially in slippery conditions).

 

The single best way to increase MPG is to drive slower. Horsepower required increases as the square of velocity, so increasing speed has an exponential decrease on MPGs. That's just how it goes and there is no tricks to get around it. If you want max MPG you need min speed. End of story.

 

As far as weight goes, it doesent matter much on flat roads. One dude quoted 0.75 MPG for 200 lbs, but I think that is quite inaccurate. Mythbusters tested this awhile back. They added 800 lbs to car and found almost no measurable difference in fuel economy on a flat road. I have hauled 3000 lbs in the back of a truck before and found no major difference in MPGs on the highway too. I wouldent worry about weight that much on flat highways. Tire pressure and speed are the two main things.

Edited by SPL Tech
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SPL Tech "would not block the intake on the CMAX on the highway (or anytime for that matter) Your CMAX will reach operating temperature really quickly on the highway. Let's just say less than 1% of your driving on a full tank spent on the Interstate is at less than operating temp. You are risking engine damage to help control heat for only 1% of the drive--completely pointless IMO."

 

I just drove to AZ and back(3,500mi) with the whole front end taped up and the highest IT  above ambient was 40*F, most of the time it was 20*F or less. I wouldn't even think about taking it off until outside temps got into the 80's. This is just another example of why you can't compare a Hybrid to a ICE car.

 

SPL Tech "Keep the tires inflated, but know if you exceed the recommended pressure too much it will cause premature tire wear and it reduces traction (especially in slippery conditions)."

 

Experience doesn't agree with this statement. I replaced my tires at 64K miles and I used 50PSI most of the time(51PSI Cold MAX on the tire), the difference in wear from the inside edge to the outside edge was less than 1/32nd and the center was even less.  Experience is always better than conventional wisdom. :)

 

Paul

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I would not block the intake on the CMAX on the highway (or anytime for that matter) Your CMAX will reach operating temperature really quickly on the highway. Let's just say less than 1% of your driving on a full tank spent on the Interstate is at less than operating temp. You are risking engine damage to help control heat for only 1% of the drive--completely pointless IMO.

 

Keep the tires inflated, but know if you exceed the recommended pressure too much it will cause premature tire wear and it reduces traction (especially in slippery conditions).

 

The single best way to increase MPG is to drive slower. Horsepower required increases as the square of velocity, so increasing speed has an exponential decrease on MPGs. That's just how it goes and there is no tricks to get around it. If you want max MPG you need min speed. End of story.

 

As far as weight goes, it doesent matter much on flat roads. One dude quoted 0.75 MPG for 200 lbs, but I think that is quite inaccurate. Mythbusters tested this awhile back. They added 800 lbs to car and found almost no measurable difference in fuel economy on a flat road. I have hauled 3000 lbs in the back of a truck before and found no major difference in MPGs on the highway too. I wouldent worry about weight that much on flat highways. Tire pressure and speed are the two main things.

This is not true. You have it backwards.

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It is true, I have had it happen on multiple vehicles. Excessive inflation causes the tire to inflate like a donught, which causes increased wear in the middle of the tire. I have seen it happen numerous times.wear_patterns.jpg

You say this after I explained my actual experience of 64K miles on my first set of tires on my CMAX with 50PSI with no wear problems, really! ;)

CMAXers want to know what members have experienced, not unrelated info on other cars. IMHO :)

 

Paul

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New tire technology has changed a lot. Gone are the old bias ply tires that were balloons.

Today's tires are designed with CAD technology. How do you think they get a PSI rated to 51 psi.

I've been running 55 psi in mine since new (4K miles) and just bumped them up to 60. My tires are

wearing even, smooth, anf flat. The car handles much better.

 

I run 75 psi in my diesel pickup. It has 10 ply tires. They wear very flat and the truck handles way better.

They're rated @ 80 psi, but that's a little harsh so I run 75 and it works great. The door label calls for

65 front and 80 rear @ max load. With the diesel engine, it's front heavy and 65 makes the tires roll

on the wheel when turning hard. It wants to wonder on the mountain roads. The extra pressure makes

it handle much better and the tires wear even without feathering the edges.

Edited by drdiesel1
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It is true, I have had it happen on multiple vehicles. Excessive inflation causes the tire to inflate like a donught, which causes increased wear in the middle of the tire. I have seen it happen numerous times.wear_patterns.jpg

 

Absolutely correct.  The maximum rated tire pressure is there for a reason--safety.  I wouldn't go higher than 44 psi on the Michelin eco tires.

 

http://www.wheels.ca/over-inflated-tires-are-a-bad-idea/

Edited by Adrian_L
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Absolutely correct.  The maximum rated tire pressure is there for a reason--safety.  I wouldn't go higher than 44 psi on the Michelin eco tires.

 

http://www.wheels.ca/over-inflated-tires-are-a-bad-idea/

Considering the tires on my car are stamped 51 PSI @ Max Load, 44 is low. Don't forget the rating has a safety margin too.

It's not gonna have any problems @ 51 or they wouldn't rate it to that number.

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Absolutely correct.  The maximum rated tire pressure is there for a reason--safety.  I wouldn't go higher than 44 psi on the Michelin eco tires.

 

http://www.wheels.ca/over-inflated-tires-are-a-bad-idea/

The maximum tire pressure is 51PSI on the sidewall of our Michelin's . Legally Michelin is not going to recommend anything different than the car manufacturer.   So 50PSI is not over inflating or a safety hazard according  to Michelin. :)

 

Paul

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