Slow Highway Cruising

[wazer]

I love to be efficient and get as many MPGs as possible on the highway with the cruise control. My previous '09 Accord was rated at 30 MPG on the highway, but I got much better than that by setting the cruise control at 60 MPH if I wasn't in a hurry. That speed gave me an average of 37 MPG, which really helped me get more miles out of a tank. Highways here have speed limits of 65/70 MPH, so I just poke in the right lane and let everyone, including the semi trucks, fly by me. Now with this Fusion Energi, it has the potential to be even more efficient at lower speeds. I've done one round trip about 60 miles away at 60 MPH and got about 45 MPG. On my last 60 mile round trip to Iowa City, I was able to to average 53-65 MPG :dance: in hybrid mode alone with the cruise control set to 50 MPH. Underneath each speed limit sign, a minimum speed of 40 MPH is listed for the interstate. I feel that I'm comfortably above that but so many people zoom by. I even got a friendly finger as someone hovered behind me, thinking I was going to get off at an exit, but instead I continued on.

 

Does anyone else take this approach to efficiency when highway cruising? or do you simply not have the time for it?

Am I crazy? Do I piss people off? I'm amazed that I've gone almost 900 miles using only 7 gallons of gas in this car.

[larryh]

Going 60 mph vs 50 mph requires about 30% more energy, so you should see the large increase in MPG that you are seeing.  The Atkinson engine used in the Energi is far more efficient than the engines used in conventional cars.  I maintain the same speed as the other cars up to the speed limit.  Only if no one is around do I go below the speed limit. 

Edited September 25, 2014 at 11:25 PM by larryh

[Russael]

In Michigan, the posted speed limit in most areas is 70, and with the way traffic seems to ignore that, it must be voluntary. ;)  I usually putz in the right lane at 65.  I've been able to pull 47MPG in hybrid mode with 2 other people in the car aside from me.  I WOULD go slower (bust it down to 60) but that's a little hazardous.  NOBODY does the speed limit.  Most do 75, and if you're in the left lane, 80.  My mother (64 years old) does 80 on the expressway.

 

I had passed a Ford Escort station wagon some years ago that was doing 55, and had signs taped in his back window about saving gas.  I'm sure he got fantastic economy.  I felt a little guilty doing my 65 passing him in my Expedition, but going slower saves gas.  Back in the 1980's, the speed limit in Michigan was 55.  I think the minimum is now 55.

 

Time is money!  Either spend some time and save some money, or spend some money and save some time.

[jeff_h]

I think I had the cruise set on either 65 or 68 on the below road trip... most commute days I set the cruise at 64 and putt along in the right lane, from my rough estimation I would say that saves about 3-5 MPG over cruising at 70... that's all I got is rough estimation, if you want numbers well that's why larryh is here. :worship:

 

[meyersnole]

Driving in the right lane and above the posted minimum speed limit, you are generally not creating issues. My only concern would be anything 20 miles below the posted speed limit. Speed differentials of 30 or more mph can be quite dangerous, especially with as much attention as some drivers are devoting to the task. Just stay safe.

 

Since getting this car I have slowed way down, as I can see the affect with all the metrics the car gives me. My speeds are situational. If I am the only one on the road and do not really have to be anywhere (I leave early to create this) then I am driving below the speed limit. In heavy traffic I tend to drive the speed limit as to not aggravate the drivers around me, unless I can drive slower with out clogging traffic. 

[blars]

It can create quite the bottleneck on busy roads with that much speed differential between the posted speed limit.  Interstates are 75 in NE and I wouldn't consider going below 70 unless it's a construction zone.  I try to keep things within a 5 mph cushion of the posted limit.

[jeff_h]

It can create quite the bottleneck on busy roads with that much speed differential between the posted speed limit.  Interstates are 75 in NE and I wouldn't consider going below 70 unless it's a construction zone.  I try to keep things within a 5 mph cushion of the posted limit.

 

I agree with you there, I stay in the right lane and am among the slower but still need to get around trucks pretty often - going a few MPH below speed limit is fine, going 20 MPH below on an interstate would be a bad idea just about anywhere.

[Fat Fusion]

Driving much below the speed limit on a highway is fairly dangerous, IMO.  I was almost rear ended one time doing above 70 by a guy doing way over 100.  And we were the only two cars on the road, early in the morning.

[Hybridbear]

I usually will drive right at the speed limit, up to 65. I don't usually exceed 65 MPH unless we're doing a long drive where the time savings of doing 70 or 75 are significant enough to make up for the extra fuel consumption. In the city I'll usually stick right at the speed limit or maybe 5 MPH over, depends on the road and the area.

 

When we first got the Fusion Hybrid I did lots of slow driving to try to maximize fuel economy. I would go 55 on the interstate where the speed limit was 70. Then I discovered that the losses of the ICE cycling on and off when driving 55 meant that MPG was barely higher than going 65 and working to keep the ICE on the entire time. So then I started driving 65. Most people in MN do 10-20 MPH over the speed limit on the freeways. There's one stretch heading toward downtown that is 55 MPH but most cars are doing 70+. The State Patrol is also out there almost 7 days a week with the radar. I am very careful to keep my speed under control there. Many people do the same on roads that are 35 MPH or less. I don't like speeding tickets so I stay away from those speeds. We see people pulled over getting tickets at least a couple times a week. I don't want to be one of them.

[Griff]

I love to be efficient and get as many MPGs as possible on the highway with the cruise control. My previous '09 Accord was rated at 30 MPG on the highway, but I got much better than that by setting the cruise control at 60 MPH if I wasn't in a hurry. That speed gave me an average of 37 MPG, which really helped me get more miles out of a tank. Highways here have speed limits of 65/70 MPH, so I just poke in the right lane and let everyone, including the semi trucks, fly by me. Now with this Fusion Energi, it has the potential to be even more efficient at lower speeds. I've done one round trip about 60 miles away at 60 MPH and got about 45 MPG. On my last 60 mile round trip to Iowa City, I was able to to average 53-65 MPG :dance: in hybrid mode alone with the cruise control set to 50 MPH. Underneath each speed limit sign, a minimum speed of 40 MPH is listed for the interstate. I feel that I'm comfortably above that but so many people zoom by. I even got a friendly finger as someone hovered behind me, thinking I was going to get off at an exit, but instead I continued on.

 

Does anyone else take this approach to efficiency when highway cruising? or do you simply not have the time for it?

Am I crazy? Do I piss people off? I'm amazed that I've gone almost 900 miles using only 7 gallons of gas in this car.

I drive 63MPH on I-95 where the limit is 65. My daily highway trip is approximately 30 miles, one way. I regularly average 50+mpg, hybrid only. They sent me a check for what again?

[Russael]

I drive 63MPH on I-95 where the limit is 65. My daily highway trip is approximately 30 miles, one way. I regularly average 50+mpg, hybrid only. They sent me a check for what again?

 

:)  Tell me what you get in February.

[shaggy314]

I go 61 to avoid you nuts driving 60...

 

I avoid the MAJOR highways and go 61. So I'd take 290 to Houston instead of IH-10, where going only 70 in the right line gets you shot AND run off the road.

 

That said, If I find a truck going 70 or left I use adaptive cruise on 1st bar (<1 second distance) and draft getting sweet mileage. Like 10-20 MPGe more using the adaptive cruise and 1 bar.

Edited October 20, 2014 at 06:56 PM by shaggy314

[wazer]

From all of your feedback, I have come to the conclusion that it's not safe to drive that much less than the posted speed limit. With that in mind, I'm going to plan some trips avoiding the interstate, sticking to the backroads which have limits of only 55.  :) Then I can save some more fuel and enjoy the beautiful countryside a bit more.

[Hybridbear]

wazer, on 05 Oct 2014 - 5:25 PM, said:

From all of your feedback, I have come to the conclusion that it's not safe to drive that much less than the posted speed limit. With that in mind, I'm going to plan some trips avoiding the interstate, sticking to the backroads which have limits of only 55.  :) Then I can save some more fuel and enjoy the beautiful countryside a bit more.

This might be our plan for our next road trip. When we did California in January 2013 right after getting our Fusion Hybrid we stuck to 55-60 in the right lane in most places to save gas. When we did our second road trip across Canada in the summer we did a maximum of 65 most days, but did 70 or 75 where the speed limits were that high on days when we were covering a lot of miles. My Fuelly history shows the corresponding hit to fuel economy, however the extra fuel was worth the time savings when we were covering 800+ miles in one day. There are so many places I want to go & see, and driving a hybrid makes the trip so much cheaper, the issue is just finding enough vacation time from work.

[meyersnole]

From all of your feedback, I have come to the conclusion that it's not safe to drive that much less than the posted speed limit. With that in mind, I'm going to plan some trips avoiding the interstate, sticking to the backroads which have limits of only 55.  :) Then I can save some more fuel and enjoy the beautiful countryside a bit more.

I just did this on my current trip. A good part of the trip was on the State and Federal highway system (non interstate) and part of it on the Appalachian Parkway. I got about 49 mpg and really enjoyed the scenery. Lots of stops and go on the parkway actually hurt my mileage, but it was worth it!

[Griff]

:) Tell me what you get in February.

I get below average Mpg in January and February. I get average mpg March and December. I blow it out of the water April-November. Check was nice, though.

[Rhynri]

I must admit, I sometimes wonder if the atkinson engine isn't a little underpowered for the fusion's portly weight.  It almost seems like having a normal 2.0l would yield better mileage in some cases because it's not working so hard to move the car.  For example, the dodge dart gets 40mpg highway (my wife owns one, I can drive fairly heavy footed and still get that number) but today I got 32mpg burning off a whole battery, getting a 98 braking score and driving like a grandmother on the same trip.  I could get 32mpg in my 2000 camaro z28 (which I no longer own) if I was careful.  My 95 cavalier is laughing as it shoots past with superior acceleration and gets 44mpg going 80. (I did that into a headwind for an entire tank, and no I'm not pulling your leg), and all I ever did to it was change the exhaust header to get rid of the straw GM installed for exhaust at the factory.  While none of these are as nice of a car, I can't help but wonder as I get 35mpg going down a hill drafting a semi why the atkinson seems to be working so hard.  Also, bar graphs suck for instant MPG.  When did numbers become 'so last year'?

[Russael]

You're kind of comparing compact cars to a mid-size car.  The Dart is compact.  The Cavalier is compact.  The Camero is a sports car, somewhat compact, designed for speed, weight savings, and aerodynamics.

 

And when you received those stellar MPG numbers, was that in summer or winter?

 

My Expo now typically receives 19MPG in the summer for highway travel.  I made a trip last year in Feb, super cold (single digits IIRC), wind howling, and I got 14 going the same speed (basically the same as I would get city travel in summer).

 

The Atkinson isn't struggling so much... it's that timing cycle that makes it noisier.  I remember reading somewhere that the car is actually de-tuned to a point because the electric motor and gas motor working together at maximum output could destroy the transmission.

 

I made a couple trips yesterday... went to a birthday party for about 3 hours.  When I arrived, I had 2 miles left on the battery.  Making a 10 mile trip home running the heat, I still netted 51MPGe by the time I pulled in the garage.  Was all surface streets.

[Rhynri]

The cavi number was dead of winter, subzero temps.  I remember it so well because I was surprised it did that well, and I didn't normally pay attention.  Even now, though at 200k+ it still gets 40+ every tank.  It could just have a one-off freak engine though.  The camaro... well, there is only one season you can drive that in and not be asking to wind up in the ditch.  :lol:  It did have a 5.7 v8 though.   That being said, the Cavalier was built 20 years ago, out of spare popcans and whatever else GM could scrape together, and I'd expect the fusion to beat what I can get out of the cavalier with my foot flat to the floor. I'd also argue that while the dart has a compact interior, it's a relatively big car (bigger in every dimension than my Sportwagen was), and while it's 500 lbs lighter than the fusion, it doesn't have a CVT or a battery and can't shut it's engine off on the downhills, or stoplights, or anywhere else.

I wasn't going off noise, if I was then the dart is working its ass off just idling. :lol:  Seriously, that thing sounds like a helicopter is flying over my house when it pulls into the garage because of the low tones, it's got quite the growly engine.  I know that the atkinson is loud because of how it works. On the Energi, just watching the RPMs vs speed fluctuate makes it look like the engine is working itself.  I seem to have little benefit to going down a hill vs going up one so long as the engine is running, which is very odd in my mind no matter what engine you have in the car.  I also don't see any difference when I am behind a big vehicle such as a semi to break the wind for me, at least not one that you can resolve on the MPG bar graph.

I am beginning to wonder if I don't have a CVT problem though.  At 3000 miles, I'm still smelling burnt rubber after every decent accelleration (and no, I'm not stomping on it, just giving it enough gas to be 60-65 at the end of a downhill on-ramp I use, not even breaking 4k rpm).

Edited January 12, 2015 at 05:03 PM by Rhynri

[Fat Fusion]

Something is wrong with your car.  You shouldn't smell anything.  

 

I have to work hard- ie: drive over 80 to get lower than 40 MPG on gas alone.

[Rhynri]

I asked the rep about it, she says that a light smell isn't out of the ordinary for the first few drives, but I shouldn't still be smelling it.  I'll make an appointment.

[Rhynri]

My trip meter on the way home read 55.7 miles, 3.5 EV miles, 0.3 regen miles // 32.8 mpg, 1.7kWh, 98% brake score.  That's with a tailwind and the battery eating all the actual acceleration on and off the freeway.  Had the heat on as cold as I could (60F) with fan on 1 and floor vent and defrost vent selected.  Car showed zero climate-control draw.

I watched the instant MPG on the way home, on any downhill insufficient to switch to electricity, it would not crest 35 (my average for this tank - I've done a fair share of pure EV on it).  on flats it would rarely peak above 30, and uphills it would occasionally turn yellow.  RPMs on the engine never seemed to dip much below 2500.  This is at 70 with very few deviations.

Does this reflect other's observations?  It was around 10 degrees today.  I keep ~40 psi in my tires.  Smelled burnt rubber out of nowhere on the drive again.  Still no CEL.

It also seems to plow through EV mileage.  It takes a full charge to go 4-6 miles, even with the engine preheated with the block heater.

[Russael]

It's definitely sounding more and more like a dealer trip is in order.

 

There is a TSB out for some symptoms with the transmission, but your car isn't exhibiting one of the known ones.  One has to do with transmission fluid seepage, another has to do with a grinding sound (and that one gets a whole new transmission assembly).  Let us know what the result winds up being.

[Rhynri]

Well, it wouldn't be the first fluid seepage problem with this car, I already had to have some engine stuff replaced because it was leaking coolant and shorting out sensors.  I'll let you know what they find.

[Rexracer]

The cavi number was dead of winter,  though at 200k+ it still gets 40+ every tank.  It could just have a one-off freak engine though.    That being said, the Cavalier was built 20 years ago, out of spare popcans and whatever else GM could scrape together,  I'd also argue that while the dart has a compact interior, it's a relatively big car (bigger in every dimension than my Sportwagen was), and while it's 500 lbs lighter than the fusion, it doesn't have a CVT or a battery and can't shut it's engine off on the downhills, or stoplights, or anywhere else.

 

I am beginning to wonder if I don't have a CVT problem though.  At 3000 miles, I'm still smelling burnt rubber after every decent accelleration (and no, I'm not stomping on it, just giving it enough gas to be 60-65 at the end of a downhill on-ramp I use, not even breaking 4k rpm).

 

A couple of things. If you are measuring every tank, and still always getting 40mpg, your Cavalier is very special. On Fuelly, I would say for for model year 1993-1995 people are averaging 27mpg. I only saw 1 other car that ever got up to 40mpg.

 

Remember the hold Civic HF, they could get 50-60mpg? People always ask "why can they do it in the 80s-90s and not now?" Well many reasons. a) weight (virtually no safety equipment, no amenities, tiny car) b) the car only had what 60hp? c) emissions standards

I saw a guy claiming to have gotten 90mpg in his Civic HF!!! of course his next tank of gas he got 19mpg, but he ignored that fact, and claimed to get 90. I can get 100mpg in my Suburban also! I go and drive 100 miles, then I go to a gas station and put 1 gallon in, and Viola 100mpg! This is why don't put any weight in anyone's MPG claims unless they track every tank of fuel. The guy claiming 90, you look at his Fuelly log and he was registering 90, 19, 70, 23, 81, 28, etc etc averaging out to *gasp* wouldn't you know it, 48mpg or so.

 

I parked my Fusion next to a friends Sportwagen the other day, it dwarfed it by comparison. 12" longer, wider, etc.

 

The Dart weighs in at 3242lbs, the Energi is 3913lbs. When your using the ICE, that big battery is dead weight in the car, this is why the Energi isn't as good as they Hybrid on the highway.

 

The reason the Energi requires the Atikson engine is its ability to start/stop quickly/efficiently and without damaging the engine. Without it, you don't have what makes a hybrid a hybrid.

 

All that to say, it does sound like there is an issue with your car, you shouldn't be smelling any burning smells. I have worked really hard and not been able to get any less then 36-38mpg over the course of a trip, so getting 30 makes it sound like there is huge drag on the system.

 

But as a reminder, new cars need to break in. I noticed great efficiency improvements over new around 1-2k miles. So if your under that don't judge. Also, Cold weather kills the performance of the Energi. So again, don't judge till its warmer.