Big Jump in Gas Mileage at 6000 Miles

[Westfield 11]

It funny how when we had 2000 miles on our cars we were told that at 4000 there was a big jump in mpg. Now that we have over 4000 miles it's at 6000 miles!!! Seems to always be 2000 miles away.... Mileage is still holding steady at 29 to 30 mpg, last was 28.3

[MPrice2984]

I think the seasonal gas changes have everything to do with it. Remember George W suspended requiring seasonal gas changes a month or so ago because of the hurricanes. Lately I've gotten some sad mileage which I can only attribute to the wrong seasonal gas. Last fill up 43.7 mpg (with new fall gas), previous fill up 37.9mpg. Same route, same driver.

[randyzimmer]

Seems quicker too.
rz

[MCMarathoner]

The Oil Drum | Refining 101: Winter Gasoline

[SharonRB]

I seem to get worse mileage on tanks when I do almost exclusively highway driving. Not terrible, but one or two miles per gallon less than my usual mixed highway/stop and go driving. I'll be interested to see what happens when I go over 6,000 miles. I'm somewhere over 4,000 now, getting close to 5,000.

[124tom]

After 8300+ miles car still getting 45.83 average. I record every drop of gas,air on or off and drive in full auto all the time interstate-70% at 65mph++ 30% stop and go and even had to use reg. gas with 10% corn when we had supply problems in our area only two tank full. Use shell 93 most of the time but have used other 93 with no differance. Also I am a big guy so car is working to get me down the road.

[ritchaso]

Originally Posted by randyzimmer

Like it says, after six months of wishing the scangauge would at least flirt with a 40, I went on a four hour drive to Watertown, NY.
I got the usual results, somewhere in the 30's and 270 miles from the tank.
On the way home, I kept seeing 40's and and got close to 300 when I found a station I needed to visit. I never reset the odo so the next tank went to 630 miles!
That made an average of over 300 for two in a row after months of 250's!
I'm pretty excited with the change and have no other reason for the improvement than just breaking in. No tire pressures, no toe settings.
Tonight I topped up with a computed 43.9 and the scangauge agreed.
I'm totally amazed with the difference.
I was disappointed at 1000 miles when everyone else said something would change (and it didn't).
Anyone else have this type of experience?

I also noted a big jump in gas mileage around 6500 miles. I trhought my scan gauge was broken the last time I filled up. Scan gauge said i got 47.5 mpg. When I calculated the actual mpg it was 47.9.

I've also noticed that using the air conditioner costs me about 3mpg. The 47.9 was with air off.

[hibbie]

I am averaging 37 city driving and 41 on the highway. Using 91 (its the highest we can get here).

The more flat highway driving, the better the mileage for me. In the mountains, not so much.

[randyzimmer]

Originally Posted by jwight

Randy, you must have switched to one of those Top Tier gasolines.

I doubt the tanks at the Reservation get the latest in formulation.
Most people stay away from there because it isn't regulated by the State
and such.
Today's price $2.80 while a good price on any corner in the city is $3.69!
rz

[SmartCard]

Originally Posted by ritchaso

I also noted a big jump in gas mileage around 6500 miles. I trhought my scan gauge was broken the last time I filled up. Scan gauge said i got 47.5 mpg. When I calculated the actual mpg it was 47.9.

I've also noticed that using the air conditioner costs me about 3mpg. The 47.9 was with air off.

And lets not forget that cooler weather may bring out better gas mileage?
(3000 miles and still in the low 30's here in Kentucky...now if I can get the wife to stop using the A/C...... )