Hot weather killing fuel economy?

[dogememe]

This ^^^^^^^^^^^^

All 3 of my vehicles get the best mileage in the heat of Summer. The engine gets up to its optimum operating temperature much faster in the Summer. Cold engines drink fuel.

I’ve never noticed large differences in fuel economy by season. Then again all my ICE vehicles were fairly large. The smallest being the Escape with a 2.5. Mostly Burbs, Yukons, K1500s, Panthers… all got about the same lousy MPG no matter the weather. Now, on the Volt, any type of HVAC ruins my miles per KwH

 

[ARCOgraphite]

I

I’ve never noticed large differences in fuel economy by season. Then again all my ICE vehicles were fairly large. The smallest being the Escape with a 2.5. Mostly Burbs, Yukons, K1500s, Panthers… all got about the same lousy MPG no matter the weather. Now, on the Volt, any type of HVAC ruins my miles per KwH

We get pretty cold winters here in the North East. You do not, I would guess, given my chats with my Brother who used to live in Santa Clarita.

I have actual record keeping DIC photos of my long term fuel use average over 2000+ miles across Winter, then same in Spring thru Summer. Right now I am at 27 MPG ave running 10W30 motor oil vs. 23 MPG on thinner 5W20. And this is with almost no early morning starts as I am retired and not heading off in the early A.M.

2.0 litre high compression D.I MAZDA/FORD engine in my EcoSport 6 speed auto AWD

 

[Chris142]

Coolant temp sensor or ambient air temp sensor would be my guess

 

[Chris142]

Here, it’s been hovering near 100F with 45% humidity.

Yesterday

 

[miden851]

Absolutely agree this is the issue.

That’s what I was referring to; it’s the most current drive and if you tank is full those numbers go up and down in wild swings

These numbers they refer to a single trip

 

[ARCOgraphite]

Coolant temp sensor or ambient air temp sensor would be my guess

Agreed, Then I noticed it was a brand new car. But stuff fails.

I still think he just need some more F.E. data. And maybe try different gas. Does AZ sell E10 everywhere?

My Brother is in Gilbert just a bit East of Phoenix and it's been over 112-114 deg actual the last few weeks.

I bet that little high comp D.I turbo No Likey Dat

 

[jetman]

I've never witnessed this before in the summer, but ever since the latest heatwave I've lost a ton of MPGs with this Integra. I used to average 30-31, now I'm at 23-25 which is ridiculous for this tiny car. I realize the air is less dense, but I've never noticed this in other vehicles in the summer.

IMO its telling you something wrong.

I've made five 2000 mile round trips between south central TX and the mtns of central CO this summer in 5 different vehicles of ours (see signature). I've been doing this trip for 10+ years in this sort heat (and hotter), and the cold of winter. We get better mileage in the heat than we do in the cold.

 

[MParr]

Yesterday

Factoring in the humidity, the real feel is 108 here. Thank goodness we are finally getting some afternoon showers.

 

[carviewsonic]

Aren't most AC compressors in modern vehicles on all winter too to dehumidify?

Just repeating Skippy722’s post here, but I’ve noticed the compressor engaging only when defrost is selected. In the dry climate where I live defrost/defog isn’t used all that much. In a damp climate defrost is probably on all the time.

 

[bobdoo]

Turbo cars consume HUGE amounts of fuel when you floor it. On my Eclipse, I could literally see the fuel needle drop one needle width with just one full-throttle blast from 0 to 80ish.

 

[Revving2Redline]

forget fuel economy, I'm more worried about the horsepower loss.

 

[Nick1994]

I don’t usually get that big of a drop in the summer, but I do get one with all the remote-starting. I’ll let it idle for 10 min many a times.

 

[Number_35]

I’ve never noticed large differences in fuel economy by season. Then again all my ICE vehicles were fairly large. The smallest being the Escape with a 2.5. Mostly Burbs, Yukons, K1500s, Panthers… all got about the same lousy MPG no matter the weather. Now, on the Volt, any type of HVAC ruins my miles per KwH

You're in a temperate climate - mileage takes a huge hit here in the winter.

 

[HowAboutThis]

As others have mentioned, sample space for current tank isn't sufficient nor are the measurements accurate enough.

I typically average just under 30MPG in my Mazda3, but can have the occasional tank that is 25-26MPG. I've probably spent time idling waiting for a customer, or a part, or sitting in my car taking a conference call or similar as I'm out between tasks, etc.


Gather data from several full tanks and if really concerned, try to keep some notes on where you went and the sort of traffic conditions. I.E. interstate, urban freeway, stop and go traffic, etc. Distance traveled and time from start to destination would also give some clues.

Just some thoughts.

Or just drive and enjoy the car.

I've taken some vacation recently and without the hour of mostly freeway and highway commute each day I've dropped from about 40-44mpgs to 36-38. More short trips and short, in town highway and freeway runs. It's still in the range my car is supposed to get for town/highway. Also, I've been idling more while waiting for people to run into a store, idling to check home improvement stores while in a parking lot to see which one has the wood I need, etc. to plan where I'm heading next, etc.

He just needs to be sure and confident traffic is the same and driving route is the same and if it continues being an issue might want to look into it. But with no check engine light (which tend to trigger easily if engine or emissions issues due to laws/regulations) and such low miles on trip A, I'm leaning toward needing more info.

 

[Skippy722]

I’ve never noticed large differences in fuel economy by season. Then again all my ICE vehicles were fairly large. The smallest being the Escape with a 2.5. Mostly Burbs, Yukons, K1500s, Panthers… all got about the same lousy MPG no matter the weather. Now, on the Volt, any type of HVAC ruins my miles per KwH

My truck will easily do 17-18 average in summer, in winter driving the same route it’ll drop to 14-15. If I have to use 4x4 a lot it’ll dip to 12-13 but I think that’s more a factor of having to push through snow.

 

[ammolab]

I just did 600 miles across NM and N Texas. Cruise set to 80 MPH but slowed for several small towns. Average MPH 69.9.
I got the best mileage EVER in my 2016 Chevy SS Sport sedan ..26.1MPH. That’s with 4 people and a trunk full of luggage on a 100+ degree day. Not bad for a 415HP V8 sedan.

 

[CR94]

... Even without the AC on I notice I need to down shift on hills that I could normally make in a higher gear. ...

That's a normal, predictable effect of lower air density, to an extent .
If not for the effects of using air conditioning, fuel economy should improve with increasing temperature.

 

[The Critic]

Some powertrains are more affected by the increased A/C usage than others?

 

[Falcon_LS]

My fuel economy takes a hit as soon as the weather heats up and I usually notice a slight decrease in overall performance as well; apart from the constant use of air conditioning, hot air is not as dense. With an ambient of 120°F, air intake temperature varies between 118°F - 145°F depending on whether you're doing highway driving or stuck in traffic.

 

[Nick1994]

Some powertrains are more affected by the increased A/C usage than others?

I think the small displacement engines struggle a lot more, especially when idling. Being a 1.5L…