Summertime causing mpg and egt changes?

[bamaboy473]

During the winter/spring my egt stayed right on 400 with in-town driving and mpg showed about 18-19 around town.

With temps in the 90s, I'm now getting 500 egt and mpg is down to the 16s.

Is this temperature related or is my 2000 Ex 7.3 sloshing more fuel into the engine? If somethings thinks so, then what's the path to find out? Thanks

[Rufus]

You still have some stations in your area with the pre-07 (low sulfer diesel).
Try a tank or two and see if you get the same results.

[bamaboy473]

what stations are running what fuel? The ones I fill up at are on the main drag and pretty busy. I like the concept that a different kind of fuel is causing the diffs, but are any other listers getting the same things this summer?

[Rufus]

The last time I checked, the tomthumb on 59 just North of Gulf Shores still had the low sulfer (not the ultra low) also there was one on 98, I think it was between Elberta and Foley. Sorry I can't be more specific, it has been a couple months since I was there.
John

[bamaboy473]

I'll look for something other than ULS fuel the next time, Rufus. I hadn't heard that the difference in the fuels had any affect on mpg. Did your mpg and egt change with USL?

[Rufus]

Yes, most people had a 2-3mpg drop. I don't know about egt, I don't have a gauge.