MPG and Premium Gas

[Mbrooks420]

You have to run premium with turbos, blowers, and high compression motors.

 

[Robert]

Here in Phoenix our gas has 15% MTBE in the summer and 10% ethanol in the winter. My gas mileage is always better in the summer months than winter. It isn't due to letting my car warm up in the winter since my garage has never gotten below 60 degrees. I just get in, start it up, back out of the garage, close the door and leave (summer & winter). My A/C is also on morning and afternoon in the summer, wheras in the winter I use vent a lot more. I do have my windows rolled down frequently on the way home from work though. I know driving with your windows down is worse for highway mileage than windows up, A/C on but the two or three times a week that I drive with my windows down should be offset by the 10-15 trips a week with the A/C off or on vent.

The only thing I can figure is mine gets better mileage on MTBE than ethanol.

 

[woodychitwn]

I was just gonna say, it was the wind. There was a 10-20 MPH Eastward wind this weekend in the mid-west and if you were driving pretty much due West, you were heading straight into it. On the way back, the wind was with you and helped your economy out.

It's the same reason airplanes take 2 hours longer to cross the Atlantic going East than they do going West.

Over big distances, a little wind makes a big difference. Especially with how aerodynamic the Explorers are.

 

[Kadarom Douhrek]

Actually planes take longer going East due to that whole the Earth is spinning thing.

 

[rgiles]

Wind has a lot to do with it. Flying to Hong Kong takes longer than coming back, and the speed difference of the plane is around 100mph less going there.

 

[Kadarom Douhrek]

Um, from Newark, NJ to Hong Kong is a 13 hour flight on a 777.
From Hong Kong to Newark is an 18 hour flight on a 777.

It takes longer heading East, not West.
And remember that the jetstreams are heading East, so the wind is helping the plane on the return trip, not slowing it down.

 

[dogfriend]

There may be another reason NOT to use premium gas (other than price)

Quote from 'Ford Fuel Injection and Electronic Engine Control" by Charles Probst:

"It may even be less than desireable to use fuel with a higher octane rating than called for in the owner's manual. Recent advancements in emission control may depend on so-called "fast-burn" to reduce emissions. If you burn 92 RON when the engine is designed for 87 RON, the higher octane fuel burns slower, and may add deposits to the combustion chamber."

A couple of earlier replies in this thread mentioned the slower burn problem, but I thought that the problem with deposits might be interesting to some of you.

 

[rgiles]

Originally posted by Kadarom Douhrek
Um, from Newark, NJ to Hong Kong is a 13 hour flight on a 777.
From Hong Kong to Newark is an 18 hour flight on a 777.

It takes longer heading East, not West.
And remember that the jetstreams are heading East, so the wind is helping the plane on the return trip, not slowing it down.

That must depend on the flight path and the carrier. United flights in and out of SF take longer going to HK than returning by at least 1 1/2 hours. I believe it's around 14 hours to go to HK, and around 12 1/2 hours to return.

 

[rgiles]

Dogfriend, thanks for the info. I used to always run higher octane gas but with the new '02 X, I'm burning 87 since that's what the Owners Manual calls for. I'm always tempted to buy the higher octane stuff and I wouldn't have imagined it would cause any problem. The octane causes a delayed burn so what you said would make sense.

 

[Robert]

Originally posted by rgiles
That must depend on the flight path and the carrier. United flights in and out of SF take longer going to HK than returning by at least 1 1/2 hours. I believe it's around 14 hours to go to HK, and around 12 1/2 hours to return.

You are correct. The difference in time is because when going from San Francisco to Hong Kong, your flight path takes you west over the Pacific. When going from Newark to Hong Kong, your flight path takes you east over the Atlantic. I've been to Europe twice, Asia twice and back and forth across the US at least a hundred times and the plane always spends more time in the air when flying west as opposed to east when taking the same route.