How to calculate MPG / fuel economy formula

[debbott]

I am on an island in the Florida Keys. Therefore, short trips reduce mpg. I am currently getting 22 mpg with a 1991 gmc sonoma pickup. When you consider huge, heavy canvas, that isn't bad. Most of my trips are under 5 miles from the shop. You are right. Every detail matters and will affect youhttp://dotable.com/images/smilies/turtle.gifr mileage.Debbott

[jusnicho]

Been doing this for a while.

17-18 mpg Discovery
34-37 mpg hyundai accent

[Superfuelgero]

This has been my method for years:
1)Fillup on the fast pump setting, clicks off
2)put on lowest setting, clicks off
3) repeat #2
4)fill until fuel visible
-Stop at anytime if fuel gushes out.

Then follow the typical miles/gal. This has worked well for me over the years over the tankful (56-64). My mgpuino is going in over the Christmas holidays that should validate my data.

Problem:
Recently, I have been using shorter trips 180-250 to separate the town and highway portions of my tank. This gave expected results in town (44.8 mpg over 230 miles) due to the car lines (like a drive thru for picking kids up at school) and high speed (75-80 mph) highway (61.5 mpg over 180 miles). Problem is my normal slow speed highway version (50-65 mph, over 180 miles), is giving me numbers that seem far too optimistic (90.4 mpg). Is there something wrong with my fill-up process?

[jeff88]

There are settings on the fuel pump?

[jeff88]

Oh! These are the pumps that have the three little bumps so you can go slow, medium and fast, right?

I don't think these are allowed in CA anymore, which is why I was confused about you're talking about. We have two speeds: off and on!

[NachtRitter]

Originally Posted by jeff88

I don't think these are allowed in CA anymore, which is why I was confused about you're talking about. We have two speeds: off and on!

What? Really? Any idea why that might be?

[NachtRitter]

Huh. When I filled my gasoline car about two weeks ago, the stops were still on the nozzle. I always take advantage of that because I like to check the oil while the fuel is pumping. Must be very recent, though I can't find anything in the news. I'll have to see what I can learn about it.

Sorry, off topic...

[jeff88]

The "cruise control" is not what's been banned. The pumps used to have notches on the bottom part of the handle. For whatever reason, I can't find any articles about it though.

I do the same thing: let it pump itself, and then check my oil (and clean my windshield for good measure).

[euromodder]

Originally Posted by jeff88

Oh! These are the pumps that have the three little bumps so you can go slow, medium and fast, right?

I don't think these are allowed in CA anymore, which is why I was confused about you're talking about. We have two speeds: off and on!

In Europe, we only have 1 setting where we can lock the pump lever these days.
If you can lock it at all, as the locking feature is often removed from pumps, so you have to squeeze it during filling.

You can manually squeeze the lever a little bit and get a slower fuel flow though.
Don't the Canadian pumps allow for that ?

[Superfuelgero]

A gas cap in the handle works well as a lock if the lock has been removed. I've only had to do this a couple of times in my trucks (40 & 120 gallon tank) when the lock was broken. otherwise I'm not there long enough to worry about it.