Anyone else notice a HUGE loss in MPG, It's NOT your imagination

[hayden55]

I don't seem to notice a difference over whats explained by thicker air resistance. Tahoe Hybrid you can measure ethanol content of fuel. If ethanol content goes too high on normal vehicles they will just run lean and die. They won't get worse gas mileage they just wont run or will stall out 24/7 at first fill up on e85.
From what I've heard toyota ecu's will compensate +/- 20% on afr and all of that. Maybe a toyota would run up to 20% e85 (whatever total ethanol percent that would get you). I won't test it though. lol

[Tmugz88]

Still seeing a steady drop in my MPG in my 14 Spark. Even driving at or below the speed limit. No additional warm up in the winter I'm seeing 30-34mpg fairly consistently. I've had one long trip to IL that I seen 40s again . But it's been terrible for mpg and minus a grill block I'm not molded heavily like many here. I'd love to see 40mpg all year or close to that but this is horrible .

[serialk11r]

Originally Posted by hayden55

I don't seem to notice a difference over whats explained by thicker air resistance.

Hmmm now that I think of it, I was comparing mpg between what I thought were "basically the same" temperature (~60F vs 47F?) but the air density difference is actually a non-negligible 2% ish. So the car needs ~1% more power to move and the fuel has at least 2% less energy, so I'm only missing 4% (7% loss)...slightly colder transmission and engine oil might account for that but I have my doubts as the coolers all have thermostats built in and I blocked off much of the grille.

I'm too cheap to go fill the tank at a Shell just to see if cheap gasoline has lower density alkanes to make it cheaper, but it still feels like the gasoline is making more than a 2% difference to me.

[Phase]

I think it could be the winter gas blend. I did a trip down to Arizona and filled uk with their gas, and it was around the same temp as here in Portland the week I went, but my mpg increased dramatically. Even with snow tires still on

[hayden55]

I've thought this for so many years but yeah you'll have warm days and the gas mileage will be back. That's why I usually prefer to do my interstate voyages when it's the warmer part of the day in the winter

[Caddylackn]

Tire pressure also goes down with temperature drop. I think it is 1 psi drop per each 10 degree F drop. I can see a 40 degree drop could easily be seen on the gas gauge if the tires were not topped off.

Around here they put 10% ethanol in the gas from November until the end of March, they say it is for emission reasons. BS. I would normally see a 8 - 10% drop in mileage when I was driving a gas vehicle. I went from 320 mile tanks to about 287 mile tanks before the fuel light would come on. How is burning an extra 1.5 gallons of fuel good for the environment?

[Ecky]

Originally Posted by Caddylackn

Around here they put 10% ethanol in the gas from November until the end of March, they say it is for emission reasons. BS. I would normally see a 8 - 10% drop in mileage when I was driving a gas vehicle. I went from 320 mile tanks to about 287 mile tanks before the fuel light would come on. How is burning an extra 1.5 gallons of fuel good for the environment?

Isn't it 10% ethanol year-round? By the BTU numbers, adding 10% ethanol reduces the energy content of fuel by around 1.5%, so ~5 miles of your tank range reduction is due to the ethanol.

This is worth a watch. It gives a nuanced view on adding ethanol to fuel:

https://www.youtube.com/watch?v=F-yDKeya4SU

[hayden55]

If anybody is wondering you can test for ethanol you don't have to guess. You just get a graduated cylinder with clear markings basically and dump a bit of water on the gas. The ethanol will separate out and join the water at the bottom and you can do the math and see the percent. We get E10 year round here.
The above is why old boats ran E0. Sometimes since the ethanol boost would fall out with the water in the gas tank issue and the motors wouldn't have enough octane left in the gas to run without pinging. The new ones can pretty much run on piss though they are pretty good at pulling timing.

[Tahoe_Hybrid]

I found a better gas station I swear though the gas went to poor quality at the other stations...


the drive is further away but for sure it's far better Yes it's filling up correctly as well.

the car is getting 40-44mpg and the SUV is in the mid to high 20s with a 6.0 liter engine on the highway

<<<< -------- as you can see on my fuel log what a difference it made 10MPG difference