Hot weather killing fuel economy?

[SaberOne]

Been averaging about 114° lately and it definitely affected the mileage in my LS3 6.2. The whole air density thing’ makes the car feel like I have 600-pounds on the trunk.

 

[dbias]

That much of a drop on a new car has to be the fuel. I would try a different gas station. My new grand Cherokee will show almost thirty mpg after filling up and resetting trip a and doing some highway driving. Of course the average comes back down to twenty as more miles are put on the tank. Just being 30 miles into the tank with idling or city driving will show lower mpg

 

[dumkid]

Turbo diesels won't make as much power or get as much efficiency in the summer if it's really hot (100+) I think it's because the intercooler doesn't cool much when it's behind an a/c condenser and the air in the cooling stack is 130+

 

[BMWTurboDzl]

I've never witnessed this before in the summer, but ever since the latest heatwave I've lost a ton of MPGs with this Integra. I used to average 30-31, now I'm at 23-25 which is ridiculous for this tiny car. I realize the air is less dense, but I've never noticed this in other vehicles in the summer.

Air-to-Air intercooler getting impacted by some heat soak?

 

[zzyzzx]

I've also noticed less gas mileage lately, but I figure it's at least partially due to me running the A/C on my way to work in the morning.

 

[4strokes]

NO. It should be generally more efficient.

That car is 1-3/4 tonnes with driver and not "tiny" with size and weighs very close to the mid-sized 7th gen Accord

Just noticed it's a new car;

1.5 Turbo DI? How carbon fluffy black is the tail pipe? How is the oil level?
I say Give it another 200 mile cycle with fresh fuel.

Was this assertion Based this on the 34 mile trip as displayed on you DIC ? - That's not conclusive data.

What octane does it require? I find middle-grade (AKI r+m/2) "Premium" fuels often un-pumped and stale. So, I would use 87. Or blend you own by pumping twice 3/4 of 87 then 1/4 of 93AKI) My search shows Costco is Top Tier additised fuel. That is pretty much required these days. You didn't add any extra cleansers did you? That would be too much detergent = BAD.

Did you just replace that moly laden FF break-in oil? '
You are in the "dregs of engine wear in" where the engine is not particularly happy.

Somtimes I start my car, don't let it warm up for a 1/2 min to go closed loop and dirve off and the thing, it won't run right. Experienced this too many tomes. If I can stop, shut her down for 3-5min and reboot - many time that will get it back to good running.

But a proper running Honda? Typically No way that low on mpg. But the super high compression D.I turbos may need special care and feeding. It may be pulling timing and covering pre-ignition knock with over-fueling.

And just to be thorough, insure there are no squirrels or 'munks taking up residence in the airbox.
- Ken

My 21 CRV AWD with the similar 1.5 turbo never drops below a 30mpg avg, not as hot here mid-80s but A/C is always on.

 

[dishdude]

Got a pretty decent highway run in, 20 mi each way and still only got up to 27 MPG. I had to swing by Costco and there wasn't a line so I filled up since my range was so low. 310 miles to a tank of gas? Ridiculous.

 

[Skippy722]

310 miles to a tank of gas? Ridiculous.

 

[KrisZ]

Yeah that MPG is pathetic for sure.

I guess high ambient temperatures do have an effect on a turbocharged engine. Probably dumps fuel to cool down the charge.

An NA engine would actually improve fuel economy since it will pull in less air, but suffer some power loss.

I see OP is in Phoenix, time for an inter cooler upgrade IMO.

 

[dishdude]

Update, I am convinced it was the hot weather. This car is driven in the same manner and on the same basic trips, as soon as the temps cooled down the MPGs recovered.