Signature mpg

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
3000 miles. Right at 23 MPG. My daily commute is a combination of stop/go and 65MPH+ stretches. I think the stop/go is what is keeping the MPG down.

I was able to get ~27MPG with my previous vehicle, a BMW Z4 28I, but that required 91 Octane. With the CX-5 I'm using 89 Octane which is currently about 20% Cheaper than 91 Octane, so I'm coming out roughly equal.
Mazda says you can run 87-octane gas perfectly fine on 2.5T or you simply just waste your money.

 
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2019 Mazda CX-5 Signature
Mazda says you can run 87-octane gas perfectly fine on 2.5T or you simply just waste your money.
Actually, it just says below 87 could damage your engine. From the manual:
"Fuel with a rating lower than 87 octane (91 RON) will negatively affect the emission control
system performance and could also cause engine knocking and serious engine damage."
I guess my definition of "perfectly fine" reaches a little higher than yours. I don't consider better performance a waste of money. Otherwise I'd be driving something else.
 
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40752

After putting 2400 miles on my 2019 my average is showing 25.4. As a test I monitored a trip from Charlotte NC to Clover SC (25 miles) driving as easy as I possibly could in light traffic and was able to average 35 mpg on the trip computer. I couldn*t come close to driving like that everyday but it was interesting to see how you could improve the 25 mpg figure. Also I have been running 89 non ethanol gas.
 
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yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
Actually, it just says below 87 could damage your engine. From the manual:
"Fuel with a rating lower than 87 octane (91 RON) will negatively affect the emission control
system performance and could also cause engine knocking and serious engine damage."
I guess my definition of "perfectly fine" reaches a little higher than yours. I don't consider better performance a waste of money. Otherwise I'd be driving something else.
Look at the power graph I posted above. You don't get "better performance" with higher octane gas unless you rev your engine over 4,000 rpm. And Mazda says this in the published power curve:

ADDITIONAL HIGH-RPM PERFORMANCE IS POSSIBLE WITH HIGHER OCTANE.

* To prevent unnecessary spending on premium fuel, both power ratings are published
 
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2019 Mazda CX-5 Signature
Look at the power graph I posted above. You don't get "better performance" with higher octane gas unless you rev your engine over 4,000 rpm. And Mazda says this in the published power curve:
So, what's your point? If I wanted economy, I'd get some econo-box.
With my other car I'd spend $1-2K in mods to add 20-30 more HP. Here, I just need to push a different button on the pump and pay a few bucks more.

Around here, you have a hard time finding 91 octane, so I usually alternate between 87 (or 89) and 93 when topping at 1/2 tank. SO it's probably more diluted than pure 91.
 
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2019 CX-5 Signature
So, what's your point? If I wanted economy, I'd get some econo-box.
With my other car I'd spend $1-2K in mods to add 20-30 more HP. Here, I just need to push a different button on the pump and pay a few bucks more.

Around here, you have a hard time finding 91 octane, so I usually alternate between 87 (or 89) and 93 when topping at 1/2 tank. SO it's probably more diluted than pure 91.
I've run both 87 and 93. I would probably need a stopwatch to tell if there's any difference from 0-60, because I didn't feel it. The main advantage of the turbo is the low end torque, which is the same no matter what octane you use. Since 93 is about 60 cents a gallon more than 87 here, and I'm not tracking the vehicle, it's kind of a no brainer for me. :) If the price was say, 20 cents apart, it would probably be different.

Just to be clear, I am not criticizing you for running higher octane. If you spend enough time above 4k RPM, it's probably worth it.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
I've run both 87 and 93. I would probably need a stopwatch to tell if there's any difference from 0-60, because I didn't feel it. The main advantage of the turbo is the low end torque, which is the same no matter what octane you use. Since 93 is about 60 cents a gallon more than 87 here, and I'm not tracking the vehicle, it's kind of a no brainer for me. :) If the price was say, 20 cents apart, it would probably be different.

Just to be clear, I am not criticizing you for running higher octane. If you spend enough time above 4k RPM, it's probably worth it.
This's exactly the point, which is also Mazda's design goal of its SkyActiv-G 2.5T. When 2.5T just came out and used in gen-2 CX-9 in 2016, Mazda claimed the 2.5T is designed mainly for low-end torque which is suitable to heavy CX-9. Its research indicates most car owners won't rev the engine over 4,000 rpm, hence the relatively smaller turbo charger on 2.5T will run out of the breath over 4,000 rpm.

Since the power and torque are exactly the same under 4,000 rpm between octane 87 and 93 gas, so unless you spend enough time above 4,000 rpm, you don't get better performance.
 
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2019 Mazda CX-5 Signature
I've run both 87 and 93. I would probably need a stopwatch to tell if there's any difference from 0-60, because I didn't feel it. The main advantage of the turbo is the low end torque, which is the same no matter what octane you use. Since 93 is about 60 cents a gallon more than 87 here, and I'm not tracking the vehicle, it's kind of a no brainer for me. :) If the price was say, 20 cents apart, it would probably be different.

Just to be clear, I am not criticizing you for running higher octane. If you spend enough time above 4k RPM, it's probably worth it.
Maybe I'll feel the same after the "newness" wears off. My engine isn't even broken-in yet, so I'm not pushing things too hard. My other car is over 4K RPM a lot, but it's a manual and only develops 221 ft-lb torque (at 4400-6000 RPM). With the CX5 turbo I get that you need to really punch it to feel the extra HP, but the problem I see is you never know when you'll need/want it. Wife usually puts in low octane, so I add 93 when I fill. As I said before, it probably averages-out to near 90. I'll take the compromise between the two.
 
I live in SoCal, a lot of stop and go. I*ve been using 91 Costco gas, the dash ranges from 20-23 mpg.
That's actually not bad! I'm in SoCal too and I've typically been putting in 89 and I'm averaging 19-20 mpg. I don't stomp the gas but I'm not extremely gentle either.
 
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2019 Mazda CX-5 Signature
Getting better. So far 3 tanks down since purchase:
Trip Calculated Summary
18.8 N/A Iffy gas from dealer, and having a bit too much fun
20.3 20.56 Lots of idling w/AC, getting used to the throttle, very little hwy
22.4 23.77!! Trip seriously underestimated, quite a bit of hwy, driving more "normal" now
 

Avoidin Deer

Zoom Zoom, baby
Contributor
:
Central Virginia
:
2019 CX-5 Reserve
Getting better. So far 3 tanks down since purchase:
Trip Calculated Summary
18.8 N/A Iffy gas from dealer, and having a bit too much fun
20.3 20.56 Lots of idling w/AC, getting used to the throttle, very little hwy
22.4 23.77!! Trip seriously underestimated, quite a bit of hwy, driving more "normal" now
I have a GT-Reserve, and keep track of my mileage in a spreadsheet.

On average, I get 22.8 MPG using 87 octane, and 24.4 MPG using 93 (based on 3 tanks of each). Given that I have switched up from one tank to the next, I think the "undiluted difference" might be greater.

Regarding my spreadsheet, I calculate each tank's MPG manually, and also enter what the computer says. I then take those two figures and calculated how many cups of gas more/less I should have bought for the two MPG figures to match.

I found that while the two MPG figures do not always match on a tank-by-tank basis, they equal each other over time (after about 2,000 miles and 6 tanks of gas, they are within .08 mpg of each other). My biggest spread on an individual tank has been 1.6 MPG.

On an individual fillup basis, I once calculated that I would have had to purchase an extra 3.93 cups of gas in order for the two MPG figures to match. Then the next tank, I would have had to purchase 3.91 cups less for them to match.
The back-to-back swings have been as high as 11.52 cups more then 12.72 cups less.
The middle variance was 6.00 cups more/6.13 cups less.

So the individual tank MPG calc difference all depends on how full that tank was to start, and how full I got it at that fill up. Not all gas station lots are level. And I may have not been as patient each fill up.
 
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40752

I have a GT-Reserve, and keep track of my mileage in a spreadsheet.

On average, I get 22.8 MPG using 87 octane, and 24.4 MPG using 93 (based on 3 tanks of each). Given that I have switched up from one tank to the next, I think the "undiluted difference" might be greater.

Regarding my spreadsheet, I calculate each tank's MPG manually, and also enter what the computer says. I then take those two figures and calculated how many cups of gas more/less I should have bought for the two MPG figures to match.

I found that while the two MPG figures do not always match on a tank-by-tank basis, they equal each other over time (after about 2,000 miles and 6 tanks of gas, they are within .08 mpg of each other). My biggest spread on an individual tank has been 1.6 MPG.

On an individual fillup basis, I once calculated that I would have had to purchase an extra 3.93 cups of gas in order for the two MPG figures to match. Then the next tank, I would have had to purchase 3.91 cups less for them to match.
The back-to-back swings have been as high as 11.52 cups more then 12.72 cups less.
The middle variance was 6.00 cups more/6.13 cups less.

So the individual tank MPG calc difference all depends on how full that tank was to start, and how full I got it at that fill up. Not all gas station lots are level. And I may have not been as patient each fill up.
Wow and I thought I was ocd, lol. Just use the car fuel economy readings, life is short.
 

Avoidin Deer

Zoom Zoom, baby
Contributor
:
Central Virginia
:
2019 CX-5 Reserve
Wow and I thought I was ocd, lol. Just use the car fuel economy readings, life is short.
Once the spreadsheet has been set up, I only have to put that tank's data into it (#gals/miles driven/computer mpg).

I might stop after a while...I'm still in New Owner mode. I usually track stuff when I first get a car, and then treat it like any other familiar relationship ;) And I now know that my computer's MPG calcs are accurate.

Don't ask how I have my shopping lists set up...
 
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40752

That*s good to hear that your findings confirm the computer mpg readings. Thanks for your info and saving me some time.
I once knew a guy that put dates on his socks to track how long they lasted (wow)
 
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Avoidin Deer

Zoom Zoom, baby
Contributor
:
Central Virginia
:
2019 CX-5 Reserve
That*s good to hear that your findings confirm the computer mpg readings. Thanks for your info and saving me some time.
I once knew a guy that put dates on his socks to track how long they lasted (wow)
I'm sitting here laughing at your friend's socks. That's pretty funny.

If he was tracking the differences in price/quality, and used a Pedometer to chart out the Pennies-Per-Step, then it kinda makes sense to me. ;)

The things we do to give ourselves the illusion of control...
 

shadonoz

SkyActiv Member
Contributor
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State of Jefferson
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2017 CX-5 GT AWD+
Wow and I thought I was ocd, lol. Just use the car fuel economy readings, life is short.
Some people just enjoy statistical analysis.

And some people are retired, and altho their life is even shorter now, they have time to do what they enjoy.
 

Avoidin Deer

Zoom Zoom, baby
Contributor
:
Central Virginia
:
2019 CX-5 Reserve
Some people just enjoy statistical analysis.

And some people are retired, and altho their life is even shorter now, they have time to do what they enjoy.
I spent the second half of my career doing data analysis, after 20 years of purchasing, contracts & inventory management. People used to give me grief for doing so much in spreadsheets...but they knew who to come to for data analysis help. I've given classes in this stuff (and still do as a community volunteer).

This started just as a place for me to log my mileage, and once I accumulated some data it "just expanded." It always does, somehow.

I can enter the current price of a gallon of 87 and 93, and it will give me the spread of a representative 300 Mile Tank of gas based upon each octane's inception-to-date average mileage. (At today's prices, the upcharge for a 300 Mile Tank of 93 octane is $5.61).
 
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