CX-5 doesn't run as well in the hot humid weather

I live in Houston - its as hot and humid as it gets :) Will try 93 octane next time and report back.

It's been very hot (95+) and humid (80%+) here for last few days and I've been driving around with premium gas. Not sure whether its placebo effect, but I did notice the following.

1. Acceleration seems smoother. Not sure how else to describe it but it feels more 'buttery' than earlier :)
2. I coast a lot instead of using brakes too much and noticed the car 'stuttering' a bit while using regular gas in hot and humid weather. That hasn't happened in the past 3 days.
3. MPG has increased by 1 unit or so.

All said and done, it costs me extra $5 per tank to use premium gas. Don't think it's worth as much, but I do feel there is a (slight) difference in performance.
 
SkyActive engines pull TONS of timing in hot and humid weather. Running higher octane fuel will lessen or remove the pulled timing. Pulled timing = HP Loss
 
Couple of days ago I was driving here in Florida and had a dash temp of 103 degrees and humidity was high but I noticed no problems with the car. I was glad it has a great ac on board.
 
Noticed a difference in performance when the temp is hovering around 90 deg and the humidity is moderate to high. Car seems to stumble a bit and gas pedal needs more pressure to move the car. Not sure if it's the weather, summer blend, a/c or a "combination of all of the above".

Car seems to perform best in the 50-65 degree range.

Anybody else notice this?

Same. I get terrible hesitation. Almost unsafe. This was with 87 octane pure gas (no ethanol). I think the car hates it, lol. I put regular 87 back in and all is well. Zero mileage difference, as well.
 
OK, so this thread started in early June and I was intrigued.

This past April, I drove 2,600 miles on a trip from Minnesota down through Iowa, Missouri, Arkansas, Tennessee, Kentucky, Mississippi and back again using regular octane fuel (87). With a strong headwind for the initial portion of the trip, I average only 22.5 mpg. On the way back it was mainly around 26 mpg but eventually climbed up to around 28 mpg as it became less and less windy. Temps were cooler (40 - 80 F), humidity not very high and speeds generally 70-75.

On June 9th I left for another long trip and decided to see if premium gas (93 octane) would make any difference in how my CX-5 ran and/or mpg. On this trip I drove 3,640 miles, starting in Minnesota but mainly driving in Kentucky, West Virginia and Tennessee, returning 3 days ago (20th). The weather for the most part was quite warm (90 - 95 F), higher humidity, significant winds in many areas, many large hills and speeds were usually 70 - 80 mph. I was pleasantly surprised that, given what seemed to be tougher driving conditions, my mpg's were consistently in the 28+ range and eventually approached 30 mpg on one tankful. In additional, my CX-5 just drove "better", a term I use because it is a seat-of-the-pants observation that comes from knowing my vehicle quite well after 36k miles.

With all of the above said, there was certainly no financial benefit to using premium fuel and, in fact, it was rather financially non-beneficial! So while it was a worthwhile experiment for me, I will stick with just regular fuel from now on as the performance using it is perfectly acceptable to me.

Just thought I'd share my real-world experience.
 
OK, so this thread started in early June and I was intrigued.

This past April, I drove 2,600 miles on a trip from Minnesota down through Iowa, Missouri, Arkansas, Tennessee, Kentucky, Mississippi and back again using regular octane fuel (87). With a strong headwind for the initial portion of the trip, I average only 22.5 mpg. On the way back it was mainly around 26 mpg but eventually climbed up to around 28 mpg as it became less and less windy. Temps were cooler (40 - 80 F), humidity not very high and speeds generally 70-75.


On June 9th I left for another long trip and decided to see if premium gas (93 octane) would make any difference in how my CX-5 ran and/or mpg. On this trip I drove 3,640 miles, starting in Minnesota but mainly driving in Kentucky, West Virginia and Tennessee, returning 3 days ago (20th). The weather for the most part was quite warm (90 - 95 F), higher humidity, significant winds in many areas, many large hills and speeds were usually 70 - 80 mph. I was pleasantly surprised that, given what seemed to be tougher driving conditions, my mpg's were consistently in the 28+ range and eventually approached 30 mpg on one tankful. In additional, my CX-5 just drove "better", a term I use because it is a seat-of-the-pants observation that comes from knowing my vehicle quite well after 36k miles.

With all of the above said, there was certainly no financial benefit to using premium fuel and, in fact, it was rather financially non-beneficial! So while it was a worthwhile experiment for me, I will stick with just regular fuel from now on as the performance using it is perfectly acceptable to me.

Just thought I'd share my real-world experience.

Wonder what the results would be with mid-grade (89) fuel? I guess the question is -- is the added expense worth the better driving experience? If 89 octane was only a couple pennies more I'd say Yes but my experience is it's a least 25 - 30 cents more per gallon. 93 octane is usually about 50 - 60 cents more.
 
... This past April, I drove 2,600 miles on a trip from Minnesota down through Iowa, Missouri, Arkansas, Tennessee, Kentucky, Mississippi and back again using regular octane fuel (87). With a strong headwind for the initial portion of the trip, I average only 22.5 mpg. On the way back it was mainly around 26 mpg but eventually climbed up to around 28 mpg as it became less and less windy. Temps were cooler (40 - 80 F), humidity not very high and speeds generally 70-75.
...
Just thought I'd share my real-world experience.
Thanks for sharing your real-world fuel consumption experience for your long trips with different grade of gasolines. Your fuel consumption with your CX-5 AWD during the trip with regular gas is in line with my experience, and in no way we can match the EPA highway estimate at 30 mpg although some others with AWD claimed they can easily meet and beat 30 mpg during their road trips.
 
OK, so this thread started in early June and I was intrigued.

This past April, I drove 2,600 miles on a trip from Minnesota down through Iowa, Missouri, Arkansas, Tennessee, Kentucky, Mississippi and back again using regular octane fuel (87). With a strong headwind for the initial portion of the trip, I average only 22.5 mpg. On the way back it was mainly around 26 mpg but eventually climbed up to around 28 mpg as it became less and less windy. Temps were cooler (40 - 80 F), humidity not very high and speeds generally 70-75.

On June 9th I left for another long trip and decided to see if premium gas (93 octane) would make any difference in how my CX-5 ran and/or mpg. On this trip I drove 3,640 miles, starting in Minnesota but mainly driving in Kentucky, West Virginia and Tennessee, returning 3 days ago (20th). The weather for the most part was quite warm (90 - 95 F), higher humidity, significant winds in many areas, many large hills and speeds were usually 70 - 80 mph. I was pleasantly surprised that, given what seemed to be tougher driving conditions, my mpg's were consistently in the 28+ range and eventually approached 30 mpg on one tankful. In additional, my CX-5 just drove "better", a term I use because it is a seat-of-the-pants observation that comes from knowing my vehicle quite well after 36k miles.

With all of the above said, there was certainly no financial benefit to using premium fuel and, in fact, it was rather financially non-beneficial! So while it was a worthwhile experiment for me, I will stick with just regular fuel from now on as the performance using it is perfectly acceptable to me.

Just thought I'd share my real-world experience.

Higher humidity decreases our octane requirements while dryer air will increase them, so the combination of higher humidity and higher octane might have given you a slight boost. I'm running 93 now and see a slight increase in mpg, I think mainly because of the hilly terrain I drive on, timing isn't being pulled as much in the warmer weather as with the 87, I'll have to connect my scangauge and check timing sometime. I see no benefit in cooler weather, particularly when it's damp or rainy. But I agree, there is no real financial benefit to stray from the 87 even though 93 might cost a measly 6 dollars more per tank, for me anyway. The engine management system does a good job IMO. The advertised horsepower and fuel mileage is available waiting for the right conditions to become evident.
 
Last edited:
Glad I dropped by to make a post and see this thread. The past few weeks I've pulled out into oncoming traffic that would normally be okay based on their distance only to have the CX-5 lag. I've got to give the higher octane a try.
 
Thanks for sharing your real-world fuel consumption experience for your long trips with different grade of gasolines. Your fuel consumption with your CX-5 AWD during the trip with regular gas is in line with my experience, and in no way we can match the EPA highway estimate at 30 mpg although some others with AWD claimed they can easily meet and beat 30 mpg during their road trips.

I'm one of those who easily obtained 30+ mpg on a road trip last summer. Apprx 320 miles one-way. Two normal sized adults, one thirty pound dog and about 300 lbs of provisions. Driving Rt 13 through Del, Md, Virg and NC. Not interstate, just rural highway with a fair amount of stop lights. Was able to obtain a little over 31 mpg on the trip.
I was babying it though and this was before the first oil change. Now with mostly suburban driving I'm see about 24.5 mpg. Still much better than my Maxima and a little better than my wife's CR-V.
 
I'm one of those who easily obtained 30+ mpg on a road trip last summer. Apprx 320 miles one-way. Two normal sized adults, one thirty pound dog and about 300 lbs of provisions. Driving Rt 13 through Del, Md, Virg and NC. Not interstate, just rural highway with a fair amount of stop lights. Was able to obtain a little over 31 mpg on the trip.
I was babying it though and this was before the first oil change. Now with mostly suburban driving I'm see about 24.5 mpg. Still much better than my Maxima and a little better than my wife's CR-V.
On your way to the Outer Banks by any chance?
 
For the first time since owning my new 2015 Touring (May 2015) - I heard a fan running under the hood when I returned from a drive. It is not THAT hot here in East TN (83 degrees) and it has been hotter. But, like I stated, this is the first time the 'fan' or whatever it is was noticed after the engine was shut off. It ran for a little over 5 minutes. Thoughts - basically why is this the first time in over a year. Thanks!
 
For the first time since owning my new 2015 Touring (May 2015) - I heard a fan running under the hood when I returned from a drive. It is not THAT hot here in East TN (83 degrees) and it has been hotter. But, like I stated, this is the first time the 'fan' or whatever it is was noticed after the engine was shut off. It ran for a little over 5 minutes. Thoughts - basically why is this the first time in over a year. Thanks!
I heard the same story before. But if you'd checked coolant level and it's fine, I wouldn't worry too much about it. The fan is supposed to be running to cool down the radiator after the engine is off if the coolant temperature is high. May be you just never noticed it before for some reason.
 
For the first time since owning my new 2015 Touring (May 2015) - I heard a fan running under the hood when I returned from a drive. It is not THAT hot here in East TN (83 degrees) and it has been hotter. But, like I stated, this is the first time the 'fan' or whatever it is was noticed after the engine was shut off. It ran for a little over 5 minutes. Thoughts - basically why is this the first time in over a year. Thanks!


Same here. Had the same thing happen couple months ago. Wasn't really hot, maybe 80, pulled into the garage, shut the car down and heard the fan running. Ran for about 5 minutes. Thought something was wrong but found out it's normal. Hasn't happened since so there must be a certain set of conditions to trigger it.
I also checked the coolant and it was fine.

Only thing that might of triggered it was I was idling in a parking lot for about 10 minutes waiting for my wife (with A/C on). That was about two miles from home so maybe it built up some heat and wasn't able to dissipate it on the way home.
 
wlong01 - BINGO! That is exactly the same scenario. My husband stayed in the car while I went in for some groceries. Car was idling for about 10 minutes, and we were just a few minutes from home. Thanks! (BTW - isn't it just incredible how the mpg takes a severe 'nosedive' while idling?!? I don't recall any other vehicle I've owned where the mpg was impacted to such a degree while idling. As a result - I try not to take hubby with me if he's just going to sit in the car - LOL!)
 
Last edited:
Back