There's actually some consensus around here that in certain conditions, like high heat/humidity and hill climbing, that higher octane results in somewhat better performance because otherwise the engine senses knock and pulls timing, thus reducing power. It is a fairly high compression engine so this isn't rare, especially in warm climates.
Real World MPG Testing - 2016 CX5 - GT with AWD
- Thread starter Lbear
- Start date
There's actually some consensus around here that in certain conditions, like high heat/humidity and hill climbing, that higher octane results in somewhat better performance because otherwise the engine senses knock and pulls timing, thus reducing power. It is a fairly high compression engine so this isn't rare, especially in warm climates.
Interesting. Good to know.
Werechull, Your car (and all others) are always touching the point of knock. The ECU is continually testing how far it can advance the timing for best running. Under certain conditions (load, heat, Ect) it reaches those limits very early.
Which means a lower power/torque output. Yes, our cars have 13-1 compression and were made to run on 87 just fine,,,,, but,,,,, they in fact run better under certain conditions with higher octane.
Which means a lower power/torque output. Yes, our cars have 13-1 compression and were made to run on 87 just fine,,,,, but,,,,, they in fact run better under certain conditions with higher octane.
Not true. This has been discussed before. The CX5 has a 13:1 compression ratio. That is the HIGHEST compression ratio of any mass produced gasoline vehicle in the world today. If not for the constant detuning, the engine would detonate itself to death.
When climbing grades, under heavy load, in high heat, running 91+ octane will help with detuning. It has been recorded by laptop computers during drives that the ECU in the Mazda CX5 is detuning and reducing timing at a surprising constant rate when running 87 octane. When it pulls timing, it keeps that timing pulled for another 1-2 minutes of driving.
I will spend the extra $2.00 per tankful for the 91 octane for the performance. I don't want to lose any more HP than I have to.
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- NE Indiana
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- '16 CX-5 GT FWD
Holy cow! What's the price difference between 87 and 91 octane in your area? Around here in northern Indiana I'd pay at least $0.60/gal more! My usual fill is about 12 gallons and of course the full tank for me is 14.8, so that would be between $7 and $9 per tank. I've thought about trying 91 octane but I just can't justify it.
First tank yet about 170 miles. Doing about 20.8 mpg in city. Not too worried at this point though - using lots of sport mode and owning cars on 121 Frontage. People get so mad that I run off from a stop practically 6 car lengths in 3 secs - they overspeed by 10 - 12 in city to get even lol.
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- RDX Aspec Adv.
You know that sport mode does absolutely nothing from a stop, right? The car does 0-60 in nearly 8 seconds. I honestly don't think anyone is actually trying...I mean, I like my CX-5, it's peppy for being so heavy and underpowered (relatively), due to gearing, but...it just ain't fast in any sense of the word at all.
Chris_Top_Her
Contributor
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- San Antonio, Texas
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- '15 CX-5 Miata AWD
I'm not 100% sure that is the case with the sports mode models. There is actually another ECU map in use when in sports mode. I've mentioned this before, but sports mode cars can actually have an aftermarket tune for normal and sports mode. Ovt is coming out with a race tune, that gives more output and a big cut in mpg.. it would be interesting to have a 93 tune on normal and the 93 required tune sport mode..
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- RDX Aspec Adv.
Then why are they not any faster than my 2015?
Did you buy yours as a pre owned? Rental?
just asking.
Just curious. Does your CX5 have the SPORT mode?
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- RDX Aspec Adv.
No, but it's just as fast as those that do, unless the guys with sport mode are doing 0-60 considerably faster than mid/high 7's.
I would soo get that tune!!
You HAVE to drive a CX5 that has the SPORT mode and then you can make a real world comparison. The SPORT mode change the ECU mapping and it changes a lot of parameters of the vehicle. Even the transmission shifts harder/faster in SPORT mode.
It's a cool option to have. It doesn't add HP but it completely changes the way the engine and transmission react making the engine & transmissions more responsive. Something that simply pressing the gas pedal cannot replicate. If that's all it was, there would be no need for a SPORT mode. It's more complicated than that.
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- RDX Aspec Adv.
It may feel different, but it's not any faster 0-60. In fact, I've seen tests that show it as slower in some cases. I suspect it makes no difference in 0-60 times.
Did my first road trip with the CX-5 from the bay area to Reno. Hit some bad traffic twice and stopped for coffee. I was at 29.4MPG until I hit the incline part of the drive. You quickly see how much harder the engine has to work since it dropped off to 25MPG going the same speed. I ended up getting some of that back towards the end after the summit and ended with 27.2MPG for the trip. Pretty happy with it and wouldnt be surprised if I get over 30 on the way back since I have a huge downhill section.
On a trip from San Francisco to Ashland, Bend, Portland, Vancouver BC, Olympic Nat Park, return via I5 through Grants pass to Eureka. Currently in Shelter Cove. 2273 miles with a total mpg of 30.685' hand calculated. Best leg was 33mpg on I5. Worst leg was 24.24 on I5. The difference was flat versus climbing.
2016.5 CX5 GT AWD
2016.5 CX5 GT AWD
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Doesn't matter, it's not about 0-60. Are you racing your cx5 and clocking to see how quick it hits 60? I'm guessing no. Sport mode is designed to improve everyday driving when extra torque is needed. Lbear is right. Until you've driven a cx5 with sport mode, you can't honestly measure its usefulness.
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- RDX Aspec Adv.
I was referring to the poster who was racing off of the line at stoplights. My Grand Jeep Cherokee had Sport Mode. It was called "Tow", lol. Different shift-points at part throttle, held gears longer, locked out overdrive, etc. it's not like this is a new concept.
I guess I'll find a CX5 with sport-mode and test-drive it, but I bet I find it just as annoying as Tow mode. Useless rpms burning fuel, no added power, the only thing it will do is prevent needing to downshift because it never upshifted, basically. Kindof like the tool who drives around in 2nd gear in his Porsche all the time. Every neighborhood has one. I just don't find the idea appealing to be honest, especially in a family car.
I'm amazed that people think quoting MPG means something WITHOUT also quoting the average speed for the tank(s) in question. Let me reiterate: there's a relationship between speed and fuel consumption, folks. Your comments about how fast you recall driving are next to useless.