Optimal cruising MPG

[Mazdiod2]

I have two OBII connected gauges I have used to analyze my MPG and driving habits.
Scangauge makes a model just for MPG monitoring. It has educated me on how to improve MPG

I make sure the tires are pumped up. I also removed the roof rails as I noticed that because the roof is wider at the front the air gets squeezed along the top and cuts MPG.

 

[Avoidin Deer]

I got all excited when I saw 30MPG early on with my current tank of gas, so I decided to see how much I could squeeze out of it.

I went to a restaurant about 20 miles away and took the legacy 55MPH highway and stayed off the 70MPH interstate. Fuel Monitor pegged that trip at 26.5MPG.

I've intentionally taken it easy with every aspect of my driving for this tank (much as I did during break-in). I still have over 1/2 tank left and my mileage rapidly declined to 25MPG.

Here's my mileage (per the computer) for every tank I've burned through so far.
This is not a temperature-related issue.

Month	Per Computer
March	25
April	23
April	23
April	25
May	24
June	23
June	24
July	23
July	24
July	23
August	23
August	23
September	24
September	23
September	24
October	24
October	24
November	25
November	25
November	24
December	23
December	23
December	22
January	22
January	24

Those few 25MPGs are really 24.xMPG rounded up.

It wouldn't bother me so much if this were everyone's experience.

Could be other things of my environment. Or maybe this is just how some of these cars are.

 

[rockethead26]

I have about 1500 miles on my GT-R, only about 500 of them highway miles, the rest are short trips of 3-8 miles (Flagstaff is small). My built in monitor shows right at 24 mpg. About 1100 of the miles are at 6900 feet in winter temps averaging around 35°F.

 

[Avoidin Deer]

Mine is at 23.5 and I drive at 75'-500' elevation in the middle of Virginia. I'm in the foothills of the Blue Ridge mountains...lots of roller coaster hills and curves (outsiders accurately call our roads "paved goat paths"). I consistently drive 8-12 miles per trip. Never shorter, the occasional 20 mile trip to the big city.

Virginia is way more humid that Arizona.

 

[40752]

Today I had a 200 mile highway trip with about 5 small towns I had to go through at 45. Highway speeds were between 55 to 65. Display showed 31.2 mpg at end of trip.

 

[Avoidin Deer]

Today I had a 200 mile highway trip with about 5 small towns I had to go through at 45. Highway speeds were between 55 to 65. Display showed 31.2 mpg at end of trip.

That's pretty good.
What type of terrain?
What were the temps?

 

[40752]

Coming back from NC coast so fairly flat. Temp was about 55. 93 octane fuel.

 

[Avoidin Deer]

Coming back from NC coast so fairly flat. Temp was about 55. 93 octane fuel.

Thanks!

I live about 40 miles west of Richmond. Maybe I need to take a test drive down that way and test my mileage. Been a while since I've seen The Outer Banks.

 

[Avoidin Deer]

For 12 miles at 37, you may never warm the car up to get decent mileage. Not sure why your MPG is so bad. I am averaging close to 24 MPG everywhere and that is in a car that is over 500 lbs more than your CX-5 (with the same engine).

I doubted your statement that the car would not warm up during a 12 mile drive, but I now think you may be right.

The other day I set the Fuel Economy Monitor to briefly display when the ignition is turned off; in other words, every time I turn off the car, the mileage for that trip is automatically shown.

I just got back from shopping. It's 8.1 miles one way. The air temp was 47°.

>My mileage there from a cold start was 19.
>My mileage back after being warmed up was 26.
>The only variable is that the drive there is 76' in elevation higher than my point of departure (so the ride back is a 76' decline).
>>Over an 8 mile drive, that's about 10' per mile...certainly not enough to affect mileage.

I don't know if the mileage difference is that great in the summer, but 47° is not cold enough to materially increase the amount of time it takes the car to warm up.

Maybe there's other stuff going on with the car where other settings from other inputs are causing this. But I'm really inclined to believe that (as you say) 8-12 miles is a "short trip" where mileage grossly suffers because the car is not warmed up.

That 12 mile trip to church we discussed is confirmation of this. It's only 40' higher in elevation than my home. Low mileage on the cold drive there/better mileage on the warmed-up (had not cooled off) trip back home.

It's also further confirmed by a trip I took to a party in early January. 80 miles @ 55MPH round trip with 4 of us in the car, and my seat-of-the-pants (un-monitored) guess at mileage is 27 or 28 based upon how much Trip A mileage went up. I kept wondering if there was a difference in road surfaces or what??? Maybe you found the answer.

The other variable (as others have said) is speed. All my local trips are non-stop (no traffic) 45-55MPH. The only longer trips I've taken besides that party have been on the 70-80MPH interstate, and my mileage sucked on those trips.

Now I can't wait for it to get warmer so I can verify this!

ps: I checked elevation because this area is so roller coaster that it's deceiving. I would have sworn that my 12 mile trip to church was mostly uphill all the way and that's what accounted for the mileage difference. It nets out to 40'. I am shocked.

 

[40752]

I doubted your statement that the car would not warm up during a 12 mile drive, but I now think you may be right.

The other day I set the Fuel Economy Monitor to briefly display when the ignition is turned off; in other words, every time I turn off the car, the mileage for that trip is automatically shown.

I just got back from shopping. It's 8.1 miles one way. The air temp was 47°.

>My mileage there from a cold start was 19.
>My mileage back after being warmed up was 26.
>The only variable is that the drive there is 76' in elevation higher than my point of departure (so the ride back is a 76' decline).
>>Over an 8 mile drive, that's about 10' per mile...certainly not enough to affect mileage.

I don't know if the mileage difference is that great in the summer, but 47° is not cold enough to materially increase the amount of time it takes the car to warm up.

Maybe there's other stuff going on with the car where other settings from other inputs are causing this. But I'm really inclined to believe that (as you say) 8-12 miles is a "short trip" where mileage grossly suffers because the car is not warmed up.

That 12 mile trip to church we discussed is confirmation of this. It's only 40' higher in elevation than my home. Low mileage on the cold drive there/better mileage on the warmed-up (had not cooled off) trip back home.

It's also further confirmed by a trip I took to a party in early January. 80 miles @ 55MPH round trip with 4 of us in the car, and my seat-of-the-pants (un-monitored) guess at mileage is 27 or 28 based upon how much Trip A mileage went up. I kept wondering if there was a difference in road surfaces or what??? Maybe you found the answer.

The other variable (as others have said) is speed. All my local trips are non-stop (no traffic) 45-55MPH. The only longer trips I've taken besides that party have been on the 70-80MPH interstate, and my mileage sucked on those trips.

Now I can't wait for it to get warmer so I can verify this!

ps: I checked elevation because this area is so roller coaster that it's deceiving. I would have sworn that my 12 mile trip to church was mostly uphill all the way and that's what accounted for the mileage difference. It nets out to 40'. I am shocked.

What is your total mileage history MPG? As I remember you have about 7 to 8K on your car.

 

[Avoidin Deer]

What is your total mileage history MPG? As I remember you have about 7 to 8K on your car.

Yeh, about 7,700 miles.

Manual Calculated Average= 24 MPG
Computer Calculated Average = 23.5 MPG

The Computer Calculated Average is the average of each tank's Trip A mileage, which is captured/reset at each fill up. Trip B (never reset) mileage = 23.5 MPG

I've had 6 tanks so far where the computer MPG has been over 24 MPG:
-March 31
-April 30
-Jun 19
-Sept 1
-Nov 2
-Nov 11

A pretty broad spectrum of temps. Our coldest month here is usually February, so we'll see what that brings.

 

[RedBaron]

>>Over an 8 mile drive, that's about 10' per mile...certainly not enough to affect mileage.

Not sure you can discount this, You are effectively lifting a 3400 lb (ish) vehicle - ~1.7 tons - by ten feet, every mile. That would seem to be quite a lot of energy required, actually.

 

[Avoidin Deer]

Not sure you can discount this, You are effectively lifting a 3400 lb (ish) vehicle - ~1.7 tons - by ten feet, every mile. That would seem to be quite a lot of energy required, actually.

I guess it's possible. I don't really know.

That's about 7/8 of a gallon spread between pushing the car up 80' one direction and letting it coast back down 80' the other direction.

Maybe one of these days when I feel like burning time & fuel I'll go home and then drive back once the car is warmed up. If you're right, that REALLY helps explain my low mileage. My house is a 75' drop in elevation from the entrance off the main road (according to What's My Elevation websites). I drive up it doing 10 MPH (cold engine) every single time I leave home. I think shadonoz also mentioned this as being a possible issue a while ago.

 

[aditto]

I did a 1000 mile mostly freeway roadtrip, and average cruising speed at 72mph, got 27mpg on regular.

I've estimated that I get about 23mpg cruising at 80mph, 25-27mpg crusing at 70-72mph, and 27-30mpg crusing at 70mph. Which is pretty good because my Signature is rated 27 for highway and I know the testing is always done at 55-60mph.

 

[theplayer11]

GTR bought in July, 4,000. miles...27.4 MPG running 87 octane only. Mostly rural driving.

 

[Avoidin Deer]

GTR bought in July, 4,000. miles...27.4 MPG running 87 octane only. Mostly rural driving.

For as nice as these cars are, and as much fun it is to have that power available, that's gotta make you happy.

 

[theplayer11]

For as nice as these cars are, and as much fun it is to have that power available, that's gotta make you happy.

To be honest, driving about 8k miles a year, 27 or 22 wouldn't make a difference to me...for the reasons you mention...talking less than $200.

 

[Avoidin Deer]

To be honest, driving about 8k miles a year, 27 or 22 wouldn't make a difference to me...for the reasons you mention...talking less than $200.

Same here.

I talk about my marginal mileage mostly out of envy and idle curiosity, but I'm retired and am driving about 9k miles per year now. Heck, I run nothing but 93 octane, so obviously I'm not worried about saving money...nets out to an extra $7/tank when accounting for the increased mileage, or about $225/year.

Before I moved to the country from the DC suburbs, I would never fathom putting even 5,000 miles a year on a vehicle. I lived that life until I hit 56 years old. I don't mind doubling that mileage...I've rediscovered the joy in driving without all that traffic.

 

[dougal]

Same here.

I talk about my marginal mileage mostly out of envy and idle curiosity, but I'm retired and am driving about 9k miles per year now. Heck, I run nothing but 93 octane, so obviously I'm not worried about saving money...nets out to an extra $7/tank when accounting for the increased mileage, or about $225/year.

Before I moved to the country from the DC suburbs, I would never fathom putting even 5,000 miles a year on a vehicle. I lived that life until I hit 56 years old. I don't mind doubling that mileage...I've rediscovered the joy in driving without all that traffic.

Wow, 9K a year seems like a little or maybe I am a nut. I end up driving about 35K miles per year. Yikes! I like good gas mileage because every mile costs me money!

 

[Avoidin Deer]

Wow, 9K a year seems like a little or maybe I am a nut. I end up driving about 35K miles per year. Yikes! I like good gas mileage because every mile costs me money!

I had a very rare situation in the DC area. I bought a house in an old neighborhood that ended up being centrally located to tons of Northern Virginia job opportunities that sprung up around it during the 35 years or so I lived in it. My most recent job commute (before moving to the country) was 3 miles each way.

I would put about 5,000-7,000 miles a year on my vehicles. Looking back on it, that's how I got away with driving cheap, old beaters for so many years.

So, yeh, I look at 9,000 miles a year as a retired guy with no daily commute and think it's pretty high!! I'm not sure where the heck I've been going!!!