Going on a long trip on the expressway with a full load!

[Recumpence]

Hey Guys,

 

My family is going on a road trip for Thanksgiving today. We are driving 400+ miles on the expressway. We are leaving today and coming home Sunday. The entire trip will be over 900 miles. This will be the worse case scinerio for our beloved Max. The car will have 5 people and a FULL compliment of luggage. And, when I say full, I mean totally Maxed out (pun intended)!  :)   The entire cargo area will be loaded to the headliner. On top of the 70mph speed and fully loaded car, the temperature is in the 20s. So, this will be the untimate mileage killer for the car. I am hoping for 40mpg on this trip at 70mph. I think the cold weather, high speed, and high load of the car will make this difficult. But, the aero mods I have done should make it a bit more doable.

 

I will post pictures and updates as I have them.

 

Wish me luck!

 

Matt

[bemyax]

Your person-miles per gallon should be astounding. May the wind be at your back.

[Recumpence]

The car is loaded. It is 17 degrees out.........

 

BBBRRRRR!!!!

 

Matt

[fotomoto]

I had mine loaded up the same way for a summer vacation plus a cargo carrier.  You may remember the pic:

 

 

 

 

Anyway, speeds were 75-80mph on I-10 and I netted about 35mpg.  So there's your low bar to surpass.   :shift:

Edited November 27, 2013 by fotomoto

[Recumpence]

Sweet!

 

I will keep you posted.

 

Matt

[frbill]

Safe journey!

[Adair]

Be safe Matt! Hope it's warmer where you're going!

[Recumpence]

We are going to Minnesota.

 

300 Miles so far at 40.1mpg driving 70 to 75mph.

 

Matt

[Adair]

We have family in MN. I try to avoid going there after September :>)

[Laurel]

Have a safe and enjoyable trip.  Your mileage is stellar.  We live in a very mild winter climate with rain and temps usually in the 40's F (Pacific Northwest) and our average winter mileage is about 35 mpg.

[Recumpence]

We arrived at 41.5mpg. the elevation is higher here than back home. So, I expect to see higher mileage on the return trip.

 

Matt

[salsaguy]

did you have the TSB all applied for better winter mileage? if so that should help a bit. hope you have fun. don't worry about mileage to much. drive safe. Happy Holidays.

[hybridbear]

Whereabouts in MN did you come? Should be better weather for traveling Sunday too as it's supposed to be close to 40. That's really impressive to get over 40 MPG at those speeds.

[Recumpence]

We are in Lichfield right now. My wife's family lives in Dassel.

 

There is a huge difference in mileage between 60mph and 70mph. I mean HUGE. The added drag is very pronounced.

 

The weight makes a big difference, too. Our luggage and 3 kids combined weigh about 500 pound minimum, plus my wife and I. I would say with one person and no luggage, the mpg would improve by around 2mpg or so.

 

So, With five people at 41.5mpg, we averaged 207mpg per person. :)

 

Matt

[asb]

41!!!  I'm impressed. The last time I had the car loaded like that, it really screamed at me.

[JAZ]

Same here, asb:  just returned from a Texas trip and saw indicated mpgs of low to mid-30s carrying a load similar to Recumpence.  Actual economy (by the pump) ranged from upper 20s to low 30s, though urban driving in Houston I could achieve the 40s.  Did my interstate driving at 70 - 77 using ECO Cruise, and while I made the time I wanted, I sure missed the mpgs I get around town here at home.

[Recumpence]

I am back home. My return mileage was 44.7MPG. So, my round trip mpg average was 43.1mpg. I could not be happier.

 

Again, this with five people and an overload of luggage. The trip each way is roughly 40 miles of 45mph driving and 370 miles of expressway averaging 70 to 75mph the whole way.

 

I cannot wait to add the air dam and kammback. :)

 

Matt

[ptjones]

I noticed the useful load of CMAX is 825lbs, sounds like you may have been over it. LOL :)

 

Paul

[Recumpence]

Well, let's add it up;

 

Me 175 pounds

My wife 150 pounds

My daughter 110 pounds

My teenage son 150 pounds

My youngest son 75 pounds

 

Luggage (guessing) 250 pounds at least.

 

So, yes, I was over it just a touch.   :)

 

Oh, remember, the weather was 25 degrees average for the whole trip.

 

Also, I have 42,500 miles on my car at this point and my lifetime mpg is 49.3.

 

Matt

Edited December 2, 2013 by Recumpence

[frbill]

So, yes, I was over it just a touch.   :)

 

Matt

 

So like most things Matt, you take things to the limit (hypermiling, aeromodding, etc.) So glad there are folks willing to take things to the cutting edge!

[ptjones]

Well, let's add it up;

 

Me 175 pounds

My wife 150 pounds

My daughter 110 pounds

My teenage son 150 pounds

My youngest son 75 pounds

 

Luggage (guessing) 250 pounds at least.

 

So, yes, I was over it just a touch.   :)

 

Oh, remember, the weather was 25 degrees average for the whole trip.

 

Also, I have 42,500 miles on my car at this point and my lifetime mpg is 49.3.

 

Matt

Nice job and it looks like you are going to catch up with me mileage wise, I've still got a week and a half till I get my car back. :sad:

 

Paul

Edited December 2, 2013 by ptjones

[Recumpence]

Hah, I will have at least another thousand miles on my car by then. :P

 

Matt

[Adair]

I am back home. My return mileage was 44.7MPG. So, my round trip mpg average was 43.1mpg. I could not be happier.

 

Again, this with five people and an overload of luggage. The trip each way is roughly 40 miles of 45mph driving and 370 miles of expressway averaging 70 to 75mph the whole way.

 

I cannot wait to add the air dam and kammback. :)

 

Matt

I am really happy for you Matt, but I don't get it. Our last trip to Indy was in early October. Weather was mild, highway new and fairly flat. 3 people weighing approx. 440lbs.,  w/luggage. 68-72 MPH. Air on the outbound, recirc on the return, and I got 34.9 MPG. And this was after all the upgrade. I have 14,400 miles on the car. I need you to come drive my car and see what I'm doing wrong.

[Recumpence]

Well, that is a good question (what you may be doing wrong).

 

Honestly, I am totally open to getting together at some point for a C-Max mini gathering. I am an hour northwest of Chicago.   :)

 

First, let me tell you, I am not lying or exadurating what-so-ever. In fact, my mileage would have been better but for a few things. For one, I did virtually no drafting other than coming closer to the rear of various large vehicles before passing them and gaining a tiny boost at that point. But, I purposely did not draft through this trip so I could make sure my numbers were not skewed.

 

I would say about 5mpg of my mileage was from the aero mods. Beyond that, there are a few things I do specifically to increase my mileage on the highway.

 

First, I allow the car to speed up going down hills, then I let it slow down a bit climbing the next hill. Going through Wisconsin there are alot of rolling hills to achieve this.

 

Second, I drive by sort of feeling what the car is doing. I watch my acceleration to not achieve more than 2 bars if at all possible. This gives acceleration and regen (battery charging) at the same time. Sometimes this is not possible with a huge load trying to get up to 70mph. But, I do it whenever possible.

 

Third, and I do not have a clue how thise works, I watch my mpg screen and I slightly speed up and slightly slow down (very gradually so it is not noticeable to anyone in the car) and I watch the screen to see when it reads over 40mpg at the speed I want and I hit Eco-Cruise at that point. There is something about these Atkinson cycle engines that the valve timing does something special at a given rpm and load that makes it additionally efficient. However, it does not just kick in when you are crusing. I am not sure what is going on with it. But, I can be driving 70mph on a given road that is relatively level and see 34mpg for miles, then all of a sudden I see 42 to 44mpg without anything changing in the state of charge, terrain, or speed. I have learned that must have something to do with the Atkinson cycle kicking in because my engine rpm does not change much (maybe 10%) at that point. I just look for that and use it to my advantage.

 

These things are not hugely time consuming to do while driving. But, they seem to increase mileage around 2mpg or so on the highway.

 

Beyond that, I have learned how to run the AC in an efficient way. In the winter, AC is not run. So, that did not contribute to this trip at all.

 

Oh, one other thing, defrost runs the AC. Watch your power consumption. You will see it is HUGE when running the defrost. So, I do not run defrost if at all possible. I will turn it on for a few minutes, then turn it off. I also do not start the car until everyone is in the car and buckled up, ready to go. Then I hit the start button and start driving. This prevents the engine from running while the car is stationary because that wastes alot of gas. Of course, over the 400+ miles of each trip, that would make very little difference.

 

Matt

[ptjones]

I am really happy for you Matt, but I don't get it. Our last trip to Indy was in early October. Weather was mild, highway new and fairly flat. 3 people weighing approx. 440lbs.,  w/luggage. 68-72 MPH. Air on the outbound, recirc on the return, and I got 34.9 MPG. And this was after all the upgrade. I have 14,400 miles on the car. I need you to come drive my car and see what I'm doing wrong.

Adair,  you need Grill Covers. LOL :)  What's your tire PSI? 50psi? Do any drafting? P&G? Wax your car? Premium or Pure Gas will help 1-2mpg but not worth the money. Also driving below 70mph helps a lot,  something about 70mph and above mpg's go down FAST!  Just some ideas that will make a difference. :)   

 

Paul

Edited December 2, 2013 by ptjones