Not So Happy MPG Talk

[fusionTX]

I thought I create a thread for bad MPG experiences, since we have one for happy ones.

Maybe we can learn from not so good outings what not to do or what to improve.

 

Yesterday, I got my windows tinted in an area of town I wouldn't normally travel to.

 

It's basically all highway with lots of high overpasses. I don't remember the exact distance, but it must have been at least twelve miles, very hot day.

 

Going there I set my cruise to 65. I wasn't seeing the mileage I wanted ( I always reset my Avg MPG, so I know how I'm doing). I then reduced cruise to 62, and by the time I arrived I was a 42 MPG. Not bad.

 

Coming back was really hot. I had the A/C going, not full blast but not on the lowest. My cruise was on 62 but my average was hovering around 37 MPG. Not terrible, but dissapointing. I do think these highways in Houston with high overpasses negatively affect mileage.

Edited May 19, 2013 by fusionTX

[gadgetguy]

I thought I create a thread for bad MPG experiences, since we have one for happy ones.

Maybe we can learn from not so gat outing what not to do or what to improve.

 

Yesterday, I got my windows tinted in an area of town I wouldn't normally travel to.

 

It's basically all highway with lots of high overpasses. I don't remember the exact distance, but it must have been at least twelve miles, very hot day.

 

Going there I set my cruise to 65. I wasn't seeing the mileage I wanted ( I always reset my Avg MPG, so I know how I'm doing). I then reduced cruise to 62, and by the time I arrived I was a 42 MPG. Not bad.

 

Coming back was really hot. I had the A/C going, not full blast but not on the lowest. My cruise was on 62 but my average was hovering around 37 MPG. Not terrible, but dissapointing. I do think these highways in Houston with high overpasses negatively affect mileage.

My highway experience is about the same and unfortunately that's my daily commute. However I must say that it's still 10-12 mpg better than I ever could get from my previous car doing the same thing. I suppose when your used to 50 mpg city trips that type of mpg return is disappointing.

[fusionTX]

Any trip in the city that is over 10 miles long, and that gets below 40 MPG, will be dissapointing to me. 42 and above is really my goal.

If you think about it, 37 MPG is 21% below EPA.

[rjent]

Since my town is only about 5 miles across, and speed limits vary from 25 MPH to 40, I usually get close to 50 MPG. My daily morning ritual is 2 miles and my mileage is so erratic that I find it frustrating to figure out what the car really wants. This morning I got 70 MPG!!!! and then at noon I got 29. Now with that said, 29 is over twice my previous car was getting so I am happy about that, I was expecting more though. When I take it on the interstate at 62 to 64 MPH, I will get around 41. I was expecting more that that as well, but that is functional. I also have to add that I only have about 650 miles so far, so I have a long way to go before it is broken in.

 

One of the main "missions" I bought the car for, is for road trips. I am taking a 2500 mile road trip in July, so I am looking forward to seeing what Bee Bee will do with that.

 

Over all, I am doing many times over what the previous car was doing. I can get over EPA on some sorties, but some is way below. Hard to figure out .....

Edited May 19, 2013 by rjent

[keybman]

Totally sympathize with you, fusionTX. It was another day of 90s and way too humid. You have to run A/C or die. And you are right with the high overpasses...a lot of energy expended going uphill that does not always seem to equalize with energy saved going downhill.

 

Today, I got trips in the mid 40s instead of 50s and my lifetime MPG went down a tenth...very disappointing.

[Da0ne]

so since the car is in the dealership i drove my truck to work, first i realize the truck needed gas so that came out to $61 for 15 gallons, miles til empty 245, drive to work around 15 miles i averaged 15.9 mpg really missing my car now

[corncobs]

Currently doing another road trip but this time we had to take my wife's Explorer just because 4 adults + 1 car seat with a 2 year old and a Cattle dog / Shepard mix dog won't fit in the FFH.

 

Went down past St Louis doing the Old Route 66 tour and I'm only getting 20.6 MPG and filling the tank with 20 gallons really hurts even at 3.399 in MO.

[kuzzi]

Just filled up the bike, 39mpg for the tank (with a little spillage thanks to a funky nozzle). Car is now better than the bike, but I don't drive the car as hard.

[acdii]

We went out Sunday fridge shopping, killed the mileage on the Flex, dropped it down to 19. :( Its back up over 20 now, even with me spanking someone in a Fusion who is oblivious to the Ecoboost badge. I even gave him a head start.

[gadgetguy]

Today when I left work it was low 90's and the car had been sitting. The bottom line is that when the A/C has to run full blast to cool the interior it's an mpg killer because it sucks the battery dry so fast until the cabin cools off and the draw drops.... That coupled with having to be in a hurry yielded just over 36 mpg :cry: on my commute home. Not even worthy of a pic...

[lolder]

Today when I left work it was low 90's and the car had been sitting. The bottom line is that when the A/C has to run full blast to cool the interior it's an mpg killer because it sucks the battery dry so fast until the cabin cools off and the draw drops.... That coupled with having to be in a hurry yielded just over 36 mpg :cry: on my commute home. Not even worthy of a pic...

Open all the windows for the first few minutes with the AC off. It'll cool just as quickly with much less a mpg hit.

[gadgetguy]

Open all the windows for the first few minutes with the AC off. It'll cool just as quickly with much less a mpg hit.

Sorry I failed to mention that. I did run with windows down for a minute but too hot and humid lol... I'm spoiled...

[neod192]

Sorry I failed to mention that. I did run with windows down for a minute but too hot and humid lol... I'm spoiled...

Here's a tip for you: when you turn on the A/C, set the temperature to the outside temp or 1 degree lower. That'll bring down the humidity while keeping the Climate energy usage under that first bar.

 

You might have to set the temp to the temp in the car or close to it, if the difference between inside and outside is high. Oh and TN on the recirculate air option.

[gadgetguy]

Here's a tip for you: when you turn on the A/C, set the temperature to the outside temp or 1 degree lower. That'll bring down the humidity while keeping the Climate energy usage under that first bar.

 

You might have to set the temp to the temp in the car or close to it, if the difference between inside and outside is high. Oh and TN on the recirculate air option.

Good idea about turning the temp up. Don't know why I didn't even think of that lol....

[kuzzi]

I do that here in Houston. I set AC at 85 when outside is 95. Climate power usage never goes above the second hash mark. After it goes below the first hash, I drop it to 77 degrees and climate usage doesnt increase.

[gadgetguy]

I do that here in Houston. I set AC at 85 when outside is 95. Climate power usage never goes above the second hash mark. After it goes below the first hash, I drop it to 77 degrees and climate usage doesnt increase.

Thanks! I'll definitely try that.

[hybridbear]

Coming back from the dealer today. Most of the trip was 65 MPH highway. This is why I take the city route. This is disappointing and lowered my tank average from 55.1 leaving the dealer down to 54.6 MPG when I got back to the office

[acdii]

^^ disappointed^^^

 

That was my number today and a good one for me! LOL

[Fynack]

I thought I create a thread for bad MPG experiences, since we have one for happy ones.

Maybe we can learn from not so good outings what not to do or what to improve.

 

Yesterday, I got my windows tinted in an area of town I wouldn't normally travel to.

 

It's basically all highway with lots of high overpasses. I don't remember the exact distance, but it must have been at least twelve miles, very hot day.

 

Going there I set my cruise to 65. I wasn't seeing the mileage I wanted ( I always reset my Avg MPG, so I know how I'm doing). I then reduced cruise to 62, and by the time I arrived I was a 42 MPG. Not bad.

 

Coming back was really hot. I had the A/C going, not full blast but not on the lowest. My cruise was on 62 but my average was hovering around 37 MPG. Not terrible, but dissapointing. I do think these highways in Houston with high overpasses negatively affect mileage.

 

65mph in 2013 fusion hybrid 34mpg

65mph in 2013 es300h 44mpg

 

Guess which one is supposedly rated higher???

 

The fuelly or fueleconomy.gov numbers for the 2013 ffh dont seem to be budging even with this "optimal" weather conditions.

[corncobs]

 

65mph in 2013 fusion hybrid 34mpg

65mph in 2013 es300h 44mpg

 

Guess which one is supposedly rated higher???

 

The fuelly or fueleconomy.gov numbers for the 2013 ffh dont seem to be budging even with this "optimal" weather conditions.

That might have been the result in your car I averaged 35.9 MPG @ 65 MPH average over 2000 miles pure interstate driving. Yes I know it's not 47 but it's also not what the EPA is testing for but they should. A lot of cars would return higher MPG #s at constant Interstate speed than the current highway test cycle.

 

And please don't refer to your Fuelly stats they don't look very promising for your claims.

[milleron]

Here's a tip for you: when you turn on the A/C, set the temperature to the outside temp or 1 degree lower. That'll bring down the humidity while keeping the Climate energy usage under that first bar.

 

You might have to set the temp to the temp in the car or close to it, if the difference between inside and outside is high. Oh and TN on the recirculate air option.

Question: on traditional auto ACs, there are only two compressor speeds: on or off, and thus, only two different states of stress on the ICE. Our compressors run on an electric motor rather than drawing power from a serpentine belt. Do they function the same way -- i.e., either off or at full speed? Unless they have intermediate speeds, how does setting the temp 1° lower than outside lower the humidity without using as much power? Just asking because I'm not sure how these electric ACs work, and I've been wondering.

[milleron]

This thread looks very interesting to me because I've had so much trouble getting numbers like many posters on these forums report. However, after 1,500 miles, it occurs to me that almost all my trips are composed mainly of freeway miles. Maybe I can't get over 44 and usually get around 38-42 because of driving our suburban freeways which almost always seem to be ascending 500 feet from a river valley with upgrades that go on fairly steeply for 2-3 miles before diving back down into yet another river valley. The outer belt here resembles nothing more closely than a roller coaster.

 

I think I'll take the car out to Kansas and see what it can do there. It makes me wonder if we're really comparing apples to oranges, too. If one poster has freeway commutes like mine, and another has commutes on monotonously level streets where he can pulse and glide at 40-50 mph, I imagine that it probably would, in fact, account for differences of 15-20%. The many comparison threads to which we post are actually UNscientific in that there is zero control of variables other than the make and model of our FFHs.

[acdii]

Question: on traditional auto ACs, there are only two compressor speeds: on or off, and thus, only two different states of stress on the ICE. Our compressors run on an electric motor rather than drawing power from a serpentine belt. Do they function the same way -- i.e., either off or at full speed? Unless they have intermediate speeds, how does setting the temp 1° lower than outside lower the humidity without using as much power? Just asking because I'm not sure how these electric ACs work, and I've been wondering.

That is a good question, but it does work. The initial startup to cool down is roughly 2 Kw, and drops down to just under 1 Kw when the blower speed drops. My guess(based on the physics of AC) is that when the blower speed drops, demand on the compressor also drops since the temperature drop across the Evaporator is lower from the balance of air through it. If you have the temp set to 70 and it has to cool down from 90, the blower will force hot air over the coils at high speed, absorbing more heat that the compressor needs to pump to the condenser, which also has to have the fans on at full blast to pull cool air over them.

 

So when you do the gradual cool down, the temp drop across the coils is much slower, so it doesn't take as much energy for the compressor to pump the coolant around, and since the compressor is electric, it's draw is consistent with its load, lower load is lower current draw.

 

Think of a power saw, when you first start it you have the spike of maximum current as it winds up, but once wound up and no load, its current draw is very low, after all it just needs to spin the mass of the armature and blade, but as soon as you start cutting the motor draws more current to maintain speed, and as you apply more load to it, it draws more and when you force it to stall it will draw its maximum current. The AC works the same way, the more it is forced to cool the higher the amp draw will be. Dropping the temp gradually reduces the amount of current needed to cool.

[acdii]

This thread looks very interesting to me because I've had so much trouble getting numbers like many posters on these forums report. However, after 1,500 miles, it occurs to me that almost all my trips are composed mainly of freeway miles. Maybe I can't get over 44 and usually get around 38-42 because of driving our suburban freeways which almost always seem to be ascending 500 feet from a river valley with upgrades that go on fairly steeply for 2-3 miles before diving back down into yet another river valley. The outer belt here resembles nothing more closely than a roller coaster.

 

I think I'll take the car out to Kansas and see what it can do there. It makes me wonder if we're really comparing apples to oranges, too. If one poster has freeway commutes like mine, and another has commutes on monotonously level streets where he can pulse and glide at 40-50 mph, I imagine that it probably would, in fact, account for differences of 15-20%. The many comparison threads to which we post are actually UNscientific in that there is zero control of variables other than the make and model of our FFHs.

 

Hammer met nail!

 

Without a direct comparison to an identical driving the same route, its very hard to diagnose if there is an actual problem. What you describe as your daily commute is getting you pretty much what you can expect to get in this car. It does VERy good when in the 40-50 MPH range where you can get regen mixed in and plenty of glide. On the Interstate, you cant get this so you are only going to get what the engine itself is rated at. My rough estimate is this engine is about a 38 MPG engine.

 

For my daily drive, base on the prior 3 Hybrids, I expect 38-43 MPG on average, and I am nailing it. In the warmer temps 41-45 is my expected range, and I am nailing that as well. If you are getting 44 Highway(Interstate) then you are doing OK.

[milleron]

Well, the load on an AC compressor would never change would it? I don't think it requires any more or less work to recompress the evaporated refrigerant when it's trying to lower the temp from 85 to 80 than it does when working to lower it from 80 to 75. The fan may operate at different speeds in those two phases, but I'm working on the assumption that by far the biggest fraction of the electricity usage is by the compressor, not the fan. It's my belief that energy usage by the compressor is uniform as long as it's running.

HOWEVER, I'm no AC engineer, and that's why I'm asking if that belief is valid. In hot, humid midwest summers, the AC is going to be a major hindrance to fuel economy, so I'm really interested in knowing just how it works. I don't want to be committing any sins of commission or omission.

Edited June 22, 2013 by milleron