Graph: mpg vs mph

dougal said:
Thanks. In general, these numbers are very similar to what I have observed. One question though, are these numbers based upon average speed and MPG for a fixed distance and time? Or it is just a get up to 80 MPH and look at the real time monitor?
Click to expand...

I reset the trip computer by pressing the center of the left steering wheel toggle, then drove about 4 miles on cruise control, on a straight, level, tree-lined county road, for the < 65 mph data points. I let the car's speed settle before I reset the trip computer. There was a slight side wind, that was blocked by the high trees. On the >55 mph points, I added/subtracted the head/tailwind.

This was enough to show me if the MPG crashed at higher speeds.
 
cx-500 said:
I reset the trip computer by pressing the center of the left steering wheel toggle, then drove about 4 miles on cruise control, on a straight, level, tree-lined county road, for the < 65 mph data points. I let the car's speed settle before I reset the trip computer. There was a slight side wind, that was blocked by the high trees. On the >55 mph points, I added/subtracted the head/tailwind.

This was enough to show me if the MPG crashed at higher speeds.
Click to expand...

I drove for nearly 30 miles at 90mph. I attained 90, then re-set the trip,avg mpg, and avg. speed. Here is a video of several minutes of it with the instant trip meter set to show you how poorly it did. The industrial vacuum cleaner sound in the background is the godawful wind noise this tin can transmits to the interior at 90. There were some slight ups/downs as I went over bridges, etc. and this is reflected as you can see. This is not a car for the open road. It's great around town, though!
 
What headwind were you fighting? You can find a local amatuer weatherstation at weatherunderground.com, most of them report conditions by the minutes.
 
Thanks CX500 - with this graph I can reverse engineer what speed wifey drives based on avg. mpg!
Also was not aware of 38 ish mpg @ 45 - a good part of my commutes is 45 ish and steady traffic with maybe one light. Hence I am able to pull 29.

My observations on speed vs mpg are

Speed (mph) economy (mpg)
80 25
100 23
120 19
140 16

Sorry I dont drive above 140 due to toddler complaining about rough ride.
 
Kaps said:
Thanks CX500 - with this graph I can reverse engineer what speed wifey drives based on avg. mpg!
Also was not aware of 38 ish mpg @ 45 - a good part of my commutes is 45 ish and steady traffic with maybe one light. Hence I am able to pull 29.

My observations on speed vs mpg are

Speed (mph) economy (mpg)
80 25
100 23
120 19
140 16

Sorry I dont drive above 140 due to toddler complaining about rough ride.
Click to expand...

So if I am to believe this, I just have been driving into a 50mph headwind, and then some, to average 14.7mpg, and when I was going down-hill and got almost 19mpg doing 90, I wonder what that makes the head-wind, given also the down-hill travel?
 
Unobtanium said:
So if I am to believe this, I just have been driving into a 50mph headwind, and then some, to average 14.7mpg, and when I was going down-hill and got almost 19mpg doing 90, I wonder what that makes the head-wind, given also the down-hill travel?
Click to expand...

Since the CX-5 won't go 140 mph, I'm guessing he was just having fun...
 
Kaps said:
Bingo!

Last line was a giveaway unobtanium!
Click to expand...

Hah! Right you are. I keep forgetting this is a CX-5. Most things I've owned don't give up until 160+.

Really though, I am impressed with the CX-5 on the big end. I showed tail lights MULTIPLE TIMES to a V6 (2005-2010?) Mustang at 100+ from a 60 punch in it. That's just shameful, no-matter what trim level the pony car was!
 
Unobtanium said:
I drove for nearly 30 miles at 90mph. I attained 90, then re-set the trip,avg mpg, and avg. speed. Here is a video of several minutes of it with the instant trip meter set to show you how poorly it did. The industrial vacuum cleaner sound in the background is the godawful wind noise this tin can transmits to the interior at 90. There were some slight ups/downs as I went over bridges, etc. and this is reflected as you can see. This is not a car for the open road. It's great around town, though!
Click to expand...

Wow, so the CX-5 is not a car that does well going 90-100 MPH in Arkansas. Who would have guessed.
 
dougal said:
Wow, so the CX-5 is not a car that does well going 90-100 MPH in Arkansas. Who would have guessed.
Click to expand...

1) Wasn't in Arkansas.
2) I had hoped it could match a 1000# heavier vehicle with over 200% more engine displacement, a larger frontal area and higher cD for efficiency. Guess not.
 
Unobtanium said:
1) Wasn't in Arkansas.
2) I had hoped it could match a 1000# heavier vehicle with over 200% more engine displacement, a larger frontal area and higher cD for efficiency. Guess not.
Click to expand...

Did you ever use GPS to verify your speed?
As far as I know, the CX-5 slightly under reports speed.
So when your speedo is showing 90.. you might be at 91, or even 92.

meanwhile.. the jeep...
When I was doing 100kph on my speedo (62mph), the radar detector was reading 58mph. That's out by 4mph.
Click to expand...
http://www.cherokeesrt8.com/forums/...ealer-service/47206-speedometer-accuracy.html

When the Jeep speedo was at 90.. you were probably going under 85.

A 6-7MPH difference is huge.. much much bigger than the small difference in drag between the two cars.
 
Unobtanium said:
1) Wasn't in Arkansas.
2) I had hoped it could match a 1000# heavier vehicle with over 200% more engine displacement, a larger frontal area and higher cD for efficiency. Guess not.
Click to expand...

Not much drag difference i think it's like .2 or 3. Bigger engine sure but also running at a lower rpm for the same speed. I'd bet your cx5 engine is over 3000rpm at 90mph cruise.
 
piotrek91 said:
Did you ever use GPS to verify your speed?
As far as I know, the CX-5 slightly under reports speed.
So when your speedo is showing 90.. you might be at 91, or even 92.

meanwhile.. the jeep...

http://www.cherokeesrt8.com/forums/...ealer-service/47206-speedometer-accuracy.html

When the Jeep speedo was at 90.. you were probably going under 85.

A 6-7MPH difference is huge.. much much bigger than the small difference in drag between the two cars.
Click to expand...

I had verified the speed of both vehicles on multiple occasions using radar speed signs. It was never off more than 1mph or so at 60-70mph, and typically agreed perfectly with my speedometer.
 
Chris_Top_Her said:
Not much drag difference i think it's like .2 or 3. Bigger engine sure but also running at a lower rpm for the same speed. I'd bet your cx5 engine is over 3000rpm at 90mph cruise.
Click to expand...

Yep. Weak motor = weak mileage at touring speeds, which is what I've always said about the CX-5. Great in town, sucks on the open road. Lots of wind noise and so forth. However, it's cheap as hell overall, and once you factor in that it's burning 87 instead of 89 like the Jeep, it's still more effective, especially as most of my driving is done at 75-80 and not 90. That said, it still never reaches anywhere near EPA doing 80, which to me is weird as every other vehicle I have had comes pretty close at 80, and nails or exceeds at 70-75. This remains my only real quibble with the CX5, and Mazda has constantly backtracked, first with the alleged enhancement of the tq converter in 2016 to help highway mileage, and finally in 2017 the figures being re-rated (reduced).
 
cx-500 said:
http://ecomodder.com/forum/tool-aero-rolling-resistance.php

It takes about TWICE the horsepower at 80 mph, than to go 60 mph.
THREE times the HP from 60 to 90.

I doubt that your jeep takes almost the exact same fuel to generate those differing HP numbers. :)
Maybe by the time you get to 80/90, the dragging brakes have faded?
Click to expand...

It got around 20mpg doing 60, as I recall (I once did 55mph because I was on a long stretch of new highway (I49) that had no gas station, as it was new. Managed 23mpg! I was afeared of runnin out!), and 18-19 doing 75ish. Doing 90 made it use all 8 cylinders and that dropped it a bit to about what the CX-5 took to do 90. Maybe a little better.
 
Last edited:
So I did have a 2015 2.5 FWD CX-5 GT that averaged about 30 mpg. I think this was dependent on the break-in period (the first 1000 miles) and how I drove it overall. I don't have a heavy foot. I use cruise control as much as possible.

Now I have a 2016 AWD CX-9 GT. The first ~800 miles were awful in terms of mpg. I probably averaged 15 mpg during that period. Maybe a little more. But once I hit 1000 miles the mpg improved greatly. Today I average 24 mpg. Again, I do not have a heavy foot and I utilize the adaptive cruise control constantly.

I guess the conclusion is it all depends on how you break the car in and how you drive from that point forward. For the first 1000 miles make sure you are revving that engine. Don't floor it. Just give it gas and ease off. Then give it more gas and ease off. Drive it that way on the streets and on the freeway. Both of my Mazdas ended up with excellent gas mileage and I don't see why yours wouldn't either.

Good luck!
Stu


Sent from my iPhone using Tapatalk
 
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