A/C and MPG

[Warstud]

I decided the other day I was going to check my Mileage on the way to work with the A/C OFF. And compare it to the Mileage with the A/C ON... on my way home. BTW it's 35 miles to work. Here's what I got.

To work with the A/C off I got 22 MPG

To home with the A/C on I got 20.5 MPG

With the long commute...I was always trying to save money on gas but after this test maybe I'll go ahead and just use the A/C. Thoughts?

 

[CT8]

Try AC to work and home with out a/c

 

[Mr Nice]

Windows open = more drag. I would never turn off A/C even if I could save 1 MPG.

 

[gathermewool]

Not enough info

 

[Warstud]

Originally Posted By: gathermewool
Not enough info


What's Missing?

 

[KzMitch]

Is it uphill in one direction and downhill in the other?
Into the wind going one way, against the wind the other way.
Just 2 of many factors.

 

[gathermewool]

Originally Posted By: Warstud
Originally Posted By: gathermewool
Not enough info


What's Missing?


More than two dissimilar data points. Wind, terrain, congestion, etc all change going vs coming.

 

[KzMitch]

Correction
Into the wind - with the wind
(you know what I meant)

 

[Nick1994]

Even if my mpg dropped 10 mpg I wouldn't stop using A/C. It's 112 outside and I have black leather seats. Not happening.

 

[Shannow]

http://www.motivemag.com/pub/feature/tech/Motive_Tech_Parasitic_Loss.shtml

 

[HerrStig]

Originally Posted By: Mr Nice
Windows open = more drag. I would never turn off A/C even if I could save 1 MPG.
+1

 

[HerrStig]

Originally Posted By: Warstud
I decided the other day I was going to check my Mileage on the way to work with the A/C OFF. And compare it to the Mileage with the A/C ON... on my way home. BTW it's 35 miles to work. Here's what I got.

To work with the A/C off I got 22 MPG

To home with the A/C on I got 20.5 MPG

With the long commute...I was always trying to save money on gas but after this test maybe I'll go ahead and just use the A/C. Thoughts?
Some of us deem it unprofessional to show up in a sweat soaked dress shirt and tie for a mile and a half per gallon. If it's so troubling, buy a smaller car.

 

[Warstud]

Originally Posted By: KzMitch
Is it uphill in one direction and downhill in the other?
Into the wind going one way, against the wind the other way.
Just 2 of many factors.


Right...2 many factors that would never be equal. Maybe a weeks worth of data would be more accurate.

 

[Shannow]

Link I posted shows the power loss that the ancillaries use, and it's not insubstantial.

If if it only takes 20-30hp to motor, the losses are quite large.

 

[HTSS_TR]

If you drive about 5 MPH slower you can gain more than 1-2 MPG.

If the driving speed is below 45-50 MPH then A/C off and window down when temperature is no higher than 70-75F, otherwise A/C on to serve you.

 

[RedOakRanch]

My truck's mpg doesn't change when I sit in it running with the AC on or off! 0.0, just the way I like it...

 

[ammolab]

Originally Posted By: Shannow
http://www.motivemag.com/pub/feature/tech/Motive_Tech_Parasitic_Loss.shtml


Funny the AC lowered max rear wheel HP on those cars. Every car I have owned had a simple manifold vacuum switch that cut out the AC compressor at large throttle settings.

 

[Errtt]

I'm glad my DD takes a very small hit when using the AC. No matter, if it took a good hit in mpg, I'll still use it - I'd rather pay the extra for comfort than feel uncomfortable - I do the same for the house, I keep it cool day & night indoors all summer.

 

[dernp]

Small price to pay for being comfortable.

 

[RationalRussian]

Agreed, If showing up to work appearances are typically more important than saving a few dollars.