Seasonal Fuel Economy

[MaineFusion]

I've decided to use my Trip 2 to record my seasonal difference in fuel economy between summer and winter here in Maine. I've decided to focus on summer vs winter and will use the first day of fall (today) and the first day of spring as my two cut points between the two times of year. I am really curious to see how cold temperatures and winter driving conditions alter my overall MPG compared to summer driving.

 

While my Trip 2 isn't the complete from the first day of this past spring, it is pretty representative of this summer: Over the 4716 miles I recorded with this Trip 2, I averaged 51.5mpg and recorded 2211EV Mi (the trip EV doesn't record the thousands digit and instead rolls over at 999.9EV).

 

 

 

If I forget, remind me to post my winter Trip 2 come spring.

[MaineFusion]

Reserved for future updates if needed.

[lolder]

The mpg will decrease 2 mpg for every 10º F. the temperature lowers.

The mpg will decrease 3 mpg for every 10 mph headwind.

The mpg will decrease for wet or contaminated roads.

Winter's a birch !

Edited September 23, 2013 by lolder

[acdii]

The mpg will decrease 2 mpg for every 10º F. the temperature lowers.

The mpg will decrease 3 mpg for every 10 mph headwind.

The mpg will decrease for wet or contaminated roads.

Winter's a birch !

Theory only. If that were true, my 2010 would have only been getting 28 MPG last winter when it was getting 34-36 and summer is 42 @ 70*. The winter was in the single digits for most of the season, at least 3 months were. That would have been a 14 MPG drop. The most it ever dropped was 6-8 MPG. When it was below 0* it would still get 34 MPG.

 

Now on the 13, we shall see. On rain soaked roads though, yeah Big hit on MPG in both cars, regardless of the temps.

[MaineFusion]

Ya, I've noticed that rain soaked roads really cut MPG.

 

At temps in the 70s I can reliably get 51 - 53mpg going and coming from work. This evening the temp was 58F and I got 51 mpg. This morning the temp was 45F and I could only squeeze out 47mpg. I have observed that I can get my best MPG at about 75F.

[kbailey990]

Yeah, I'm scared to death of those Sarasota winters we have. Might see 50 this year... Brutal down here :)

[jeff_h]

The mpg will decrease 2 mpg for every 10º F. the temperature lowers.

The mpg will decrease 3 mpg for every 10 mph headwind.

The mpg will decrease for wet or contaminated roads.

Winter's a birch !

Yeah I would say this is about right, might have a bit of a curve to it (which is what I think acdii was getting at) so 2 mpg for every 10º for the first 30º, and then another 1 mpg for every 10º after that.. everyone's is different YMMV case, but newbies who are getting really good MPG, well that will change --- but will get back to where you are now when Spring rolls around.

[lolder]

My observations are from about 40º F to 95º F. I think below 40 it flattens out to the mpg that a non hybrid of the same power and weight would get boosted a little by city regen braking and the ~10% better Atkinson efficiency.

[MaineFusion]

One nice thing is that once the engine is warm, it takes almost no extra electricity to warm the cabin, unlike on a hot day where the A/C does add a noticeable draw. Admittedly this is a very small consolation prize for cold temps.

[acdii]

My observations are from about 40º F to 95º F. I think below 40 it flattens out to the mpg that a non hybrid of the same power and weight would get boosted a little by city regen braking and the ~10% better Atkinson efficiency.

Thanks for the clarification. :) The math wasn't adding up from my observations.

[hybridbear]

My observations are from about 40º F to 95º F. I think below 40 it flattens out to the mpg that a non hybrid of the same power and weight would get boosted a little by city regen braking and the ~10% better Atkinson efficiency.

I found it to be fairly constant on long highway trips. In the city the drop is much more than 2 MPG for every 10^oF drop in temp. Since the ICE has to run to stay warm and cools down so quickly when running in EV mode city mileage drops fast. City trips that at 70^oF consistently net 60+ MPG only get 35-40 MPG when the temp is <20^oF. When the temp is below 0 we found it hard to get even 32 MPG on those same trips. Based on the 2 MPG for every 10^oF those trips should still get 50+ MPG based on a 50^oF temp drop taking away 10 MPG. Instead those trips lose about 25 MPG. From 70^oF to 60^oF I have not seen any drop yet, going from 70^oF down to 50^oF I've seen about a 3 MPG drop. The big MPG hit doesn't come until you get cold enough that you're turning on the heat. At that point the heat sucks so much thermal energy out of the coolant to heat the cabin that the ICE must run and burn more gas to heat the coolant to heat the car. If you keep the heat on all the time in winter you'll see results like nmadole who averaged under 30 MPG I believe in the winter in Michigan. We would not turn on the heat until the ICE had warmed up enough to be able to still shut off even with the heat on. We would just use the heated seats for the first 10 minutes or so. We would also turn off the heat if the ICE got too cool where it wouldn't shut off normally because the coolant temp had dropped too low. Even with doing all this we averaged under 40 MPG in winter. Our worst tank was under 35 MPG. That was about a 23-24 MPG drop compared to the same driving at 60^oF. It doesn't follow a linear slope, but if it did that would work out to almost 4 MPG per 10^oF temp drop from 60^o down to 0^oF average for that worst tank.

 

 

The mpg will decrease 2 mpg for every 10º F the temperature lowers.

Back in January-April I was making quite a few trips down to Owatonna as part of a project I was working on and for each trip I recorded the ambient temp, wind direction and speed, miles, EV miles and MPG from trip summary and my cruise control speed. Since these trips were prior to the PCM update I tried keeping the Cruise Control set at 60 MPH always trying to get better fuel economy. Removing the wind impact from these trips I consistently got 36 MPG on a ~60 mile highway commute at 60 MPH from home to Owatonna for work in the winter at temps of 10-15ºF. The same trip at 30ºF was consistently 40-41 MPG. The same trip at 70ºF was consistently 48-49 MPG. At -10ºF I got 32 MPG and at 0ºF about 34 MPG. Since our weather went right from below freezing to 60s and 70s in a week back in April I don't have hardly any data with ambient temps in the 40s or 50s.

Edited September 24, 2013 by hybridbear

[acdii]

It was your results that made me know something wasn't right with the blue one, Considering your environment was much colder than mine, and you were doing better, Well that and the unexplained plug fouling. Ahh, but I has a much nicer one now, and making some covers for it this weekend too. Which reminds me, I need to get my bandsaw cleaned up and put a new band on it.

[Eddie Sessum]

Id hate to see -20 or -30*f.. You wouldnt be able to run because it would burn the fuel quicker than you could put it in...

[acdii]

Id hate to see -20 or -30*f.. You wouldnt be able to run because it would burn the fuel quicker than you could put it in...

Oh I dont know, drove in -32* temps and didnt use any more than usual.

 

[Eddie Sessum]

Yea, well according to those calculations ill get 0mpg at -30*f...

 

 

Based on the injector size on our motors. Going full speed with it to the floor at the limit we shouldnt be able to get worse than around 19mpg-ish.

 

I had a saturn sky turbo and at 145mph you STILL got 14mpg. Id figure that car is around the same aerodynamic as FFH and MKZ.

 

 

Also would like to mention the sky was actually running at around 4500rpm to the floor.. didnt have enough power to overcome the drag. So it will eating as much fuel as it could.

Edited September 24, 2013 by Eddie Sessum

[MaineFusion]

Well spring has arrived and I remembered to reset my Trip 2 on the first day of spring (3/20). From 9/22/2013 until 3/20/2014, I recorded 9120.4mi on Trip 2 using 199.41 gallons of gas giving me an average fuel economy of 45.7mpg. This is much better than I was expecting given how bad the winter was. I guess the late fall which gave me extra high MPG driving time helped to offset the beating my fuel economy took from December through February. The road trip we took to Virginia in November also helped pad on some extra high MPG miles.

.

 

--Edit note--

Corrected date range.

Edited March 22, 2014 by MaineFusion

[hybridbear]

Well spring has arrived and I remembered to reset my Trip 2 on the first day of spring (3/20). From 10/22/2013 until 3/20/2014, I recorded 9120.4mi on Trip 2 using 199.41 gallons of gas giving me an average fuel economy of 45.7mpg. This is much better than I was expecting given how bad the winter was. I guess the late fall which gave me extra high MPG driving time helped to offset the beating my fuel economy took from December through February. The road trip we took to Virginia in November also helped pad on some extra high MPG miles.

20140320_173805.jpg.

That's incredible for winter! I bet that this summer you'll beat the numbers from last summer shown in the first post.

[MaineFusion]

That's incredible for winter! I bet that this summer you'll beat the numbers from last summer shown in the first post.

The thing is I put quite a bit of mileage on in late October and November which seriously padded my winter time driving. If I had just recorded Dec, Jan and Feb, it would have been a totally different story. For those months I was doing good if I could break 40mpg. The grille cover I installed did help by making it easier to keep the car warm and probably improved aerodynamics some.

 

Later this spring, once it warms up some more, I'll be taking the grille cover off for the summer. Even though it is clear, I don't like the looks of it that much.

[ptjones]

The thing is I put quite a bit of mileage on in late October and November which seriously padded my winter time driving. If I had just recorded Dec, Jan and Feb, it would have been a totally different story. For those months I was doing good if I could break 40mpg. The grille cover I installed did help by making it easier to keep the car warm and probably improved aerodynamics some.

 

Later this spring, once it warms up some more, I'll be taking the grille cover off for the summer. Even though it is clear, I don't like the looks of it that much.

I would be interested to know the difference between Cover without holes and cover with holes. :)

 

Paul

[MaineFusion]

I would be interested to know the difference between Cover without holes and cover with holes. :)

 

Paul

 

Having used the cover for this past winter, I do have some ideas for minor changes that would improve it:

1. Provide two bolt assemblies so that it can be bolted to two different vertical slats instead of one. This would make it more secure in brushless car washes.
2. Use blocks similar to the end blocks with the bolts (drill hole down middle of block) This would allow the cover to be tightened against vertical slat without it having to come in contact with the plastic horizontal slats. This would avoid rubbing the chrome off the grille.
3. Use stronger "industrial" velcro on end blocks so that the velcro holds better.
4. Instead of attaching the velcro to the grille cover, attach it to the grille This way, when the grille cover is removed, the spacing block is also removed.

[Howie411]

So its finally getting "warm" in VA and honestly I am not noticing much difference in full economy, All throughout the winter I was between 37-40 each fill up. Now that its somewhat warm outside The 2 tanks I've gone through are only at about 39. As much as I hate to admit it my 2010 FFH seemed to a better job on gas mileage. could constantly get almost 50 and usually without trying. I can barely get 43+ with my 2014 FFH so far.

[Silver Bullet]

I'm kind of sharing your experience. We acquired our 2014 FFHSE in late December and experienced 36 - 38 mpg during break-in with studded snow tires in mountain country. I replaced the snow tires in late March with the Michelin LRR tires that came with the car and have been occasionally breaking 40 mpg since the tire change at 4800 miles. We still drive the car just as we did the 2008 Mercury Milan V-6 that preceded it, including warm-ups, climate control and mostly 55 mph rural driving with occasional 65 -72 mph freeway trips. The warmer weather seems to help, but I doubt we'll ever see the 47 mpg range that folks like Hbridbear regularly exceed.

HOpe you enjoy your FFH as much as we do ours!

[lolder]

Don't warm it up.

[Silver Bullet]

Whaddaya mean, "Don't warm it up?" Seems to me that's a personal choice. If my long-past-retirement-age bride is still willing to get up at 4:30 am to drive 25 miles over a mountain to see patients, and FoMoCo provides us with a cozy car with heated leather seats, I'll cheerfully spend a tad on gasoline while I clean the windshield to make the start of her commute a bit more comfortable.

We bought the Silver Bullet to enjoy it, not to claim bragging rights on a high mpg number.

To each his own, I reckon.

[hermans]

I agree with Silver Bullet. I don't have a obsessive compulsive disorder about the anount of gas I use when warming up the car. I've read many posts on these forums about not using the heater and only using the heated seats. Sorry, my confort comes first.

 

But then, "to each his own."

 

I do disagree with Silver Bullet when he/she makes the statement, :I'll never see 47 MPG." I often see that and much more. My average for this last Winter was 40.4 and I live in the Northeast. I reset my mileage last weekend.

Edited April 15, 2014 by hermans