Absolute best speed for the highest MPG for gasoline/petrol models?

Kedis82ZE8

'15 CX-5 AWD GT w/Tech Pkg
Contributor
Has anyone ever done some quick testing to determine what speed results in the highest MPG for both the 2.0 & 2.5L engines (gasoline/petrol models in both FWD & AWD versions)?

I am talking flat terrain, AC off, no windows open, low electrical load...

I drove like 3 miles today on flat road with cruise control on at around 35-40 MPH and noticed MPGs stayed right in the high 30's if not touching 40 once and a while.
 
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Best mileage is probably going to be the lowest speed that will stay in high gear. For mine, that's about 44 MPH.
 
I frequently hypermileage my 2013 AWD 2.0 and my girlfriend's 2015 AWD 2.5. Anything between 40-55 MPH with no head winds and upward slope will net 38+ MPG on the 2.5 and 40+ MPG on the 2.0. Realistically, 55 MPH is the bare minimum for highways.

Also, cruise control won't be as efficient for hypermileage than strategic throttling. A low speed is only half the battle for great gas mileage. Maintaining inertia without braking is the other half of the battle for efficiency.


Here are some very good tips for epic MPG:
http://ecomodder.com/forum/EM-hypermiling-driving-tips-ecodriving.php
 
Thanks for info!!! Very interesting. I was reading up on Atkinson cycle the other day and was curious since SkyActive is based on it. I guess it becomes Otto Cycle "like Millenia" with forced induction.
 
Has anyone ever done some quick testing to determine what speed results in the highest MPG for both the 2.0 & 2.5L engines (gasoline/petrol models in both FWD & AWD versions)?

I am talking flat terrain, AC off, no windows open, low electrical load...

I drove like 3 miles today on flat road with cruise control on at around 35-40 MPH and noticed MPGs stayed right in the high 30's if not touching 40 once and a while.


I have the same results as SAYNOTOPISTONS.

48-52mph seems to be the happy spot with both the CX5 2.5 and 2.0 automatics I have owned.

Check the cold tire pressures! The colder temps drop the tire pressure and zap your MPG.
 
Agreed, tire pressure does have a noticeable effect on gas mileage.

However, for my Grand Touring 2.0 with the 19" wheels I choose to run 2 psi below recommended 36psi due to the jarring roads of NYC. Girlfriend's Touring 2.5 with the 17" wheels ride well enough at recommended 36psi. Ride quality difference is not substantial, but my commute is absolutely horrid for me to justify the decrease in pressure to save some wear and tear.
 
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Almost every modern car will achieve it's highest MPG figures around 40-45 mph. That's because aerodynamic drag increases exponentially and starts to become more significant than other losses at those speeds.
 
The transmission on my 2.5 AUTO AWD, will only allow you to shift into 6th gear at above 45-46mph... So that is another explanation for the 46-50mph sweet spot...
 
The transmission on my 2.5 AUTO AWD, will only allow you to shift into 6th gear at above 45-46mph... So that is another explanation for the 46-50mph sweet spot...

Is it not possible to manually shift into 6th at say, 44mph?
 
Is it not possible to manually shift into 6th at say, 44mph?
NOPE, moving the lever repeatedly during several trials, there is no shifting until it reaches the 45 mph threshold. And it will shift back out of 6th into 5th AUTOMATICALLY even in MANUAL MODE at around 43 mph...
 
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The transmission on my 2.5 AUTO AWD, will only allow you to shift into 6th gear at above 45-46mph... So that is another explanation for the 46-50mph sweet spot...

That's odd. My 2013 AWD 2.0L will hold 6th gear all the way down to about 30 mph as long as I am gentle on the accelerator. And it allows me to shift up into 6th gear as low as 35 mph. This is useful for descending long gentle grades at slower speeds once the engine is fully warm.

This behavior is exactly as detailed on page 162 (4-38) of my owners manual. Did they change the manual shift mode of the 2.5L automatic to make it behave more like an automatic?
 
The transmission on my 2.5 AUTO AWD, will only allow you to shift into 6th gear at above 45-46mph... So that is another explanation for the 46-50mph sweet spot...

Another reason I wanted a manual transmission. I usually keep it in 5th gear at 30mph and 6th by 35 mph. Helps a lot in achieving good mpg.
 
My 15 touring does 46 mpg when I'm going around 45 mph on cruise control. tested it many times driving at night with no traffic and not many street lights. Its at 5th gear at that speed.
 
I had this over the course of 120 mile trip.

http://i1294.photobucket.com/albums/b619/dadofjon/IMAG0103_zps037zsz2u.jpg

a couple of stretches of 50mph average speed cameras helped.

The diesel doesn't like sitting much lower than 50mph in 6th gear. Forgot to take a pic of average speed :doh:

72.4 MPG = 60.3 MPG for us Americans and our small gallons..
Nice high number!

The highest I've seen on a round trip with my 2.0L gas model was 47MPG. (driving in heavy LA traffic at 45MPH average speed)
 
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I frequently hypermileage my 2013 AWD 2.0 and my girlfriend's 2015 AWD 2.5. Anything between 40-55 MPH with no head winds and upward slope will net 38+ MPG on the 2.5 and 40+ MPG on the 2.0. Realistically, 55 MPH is the bare minimum for highways.

Also, cruise control won't be as efficient for hypermileage than strategic throttling. A low speed is only half the battle for great gas mileage. Maintaining inertia without braking is the other half of the battle for efficiency.


Here are some very good tips for epic MPG:
http://ecomodder.com/forum/EM-hypermiling-driving-tips-ecodriving.php

I find that MPG does not decrease when going 70-80MPH because this keeps the revs closer to the powerband in the 2.5L
 
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