Riddle me this..MPG puzzle

Just so I don`t have to do ANOTHER 300 mile MPG test drive let me get anyones (Maybe a math guy) opinion on this.
So I wanted to check the MPG average of 2 different type fuel injectors (The types and part #'s being unimportant at this time.) So last weekend had set #1 in and drove 300 miles in a big circle (Visited the casino up in WV so not just a total waste of driving). Did the math and found I averaged 19.75MPG HIGHWAY. Refilled and drove back and forth to work all wekk and found that I averaged 14.47MPG CITY.
So..... This weekend installed set #2 in and drove the exact same 300 mile circle. Averaged 18.52MPG HIGHWAY, BUT I got stuck in 2 long traffic jams because of accidents which caused me to drive stop and go from between 0-20MPH for a total of 45 minutes!

SOOOO the question is even though set #1 averaged 1.25MPG more on the highway does the 45 minutes of city-like driving (Which would have dragged the MPG down to below 15) mean that set #2 was actually better?..Or maybe they were the same? Or there's no way of knowing?

They seem to be pretty close...unfortunately, with the extra variables, there is now some guess work. Obviously, the only way to know for sure is put them both through exactly the same circumstances.

To better know, you need to rerun the 300 mile loop again, in traffic conditions similar to the first loop.
Bear in mind that there is a be normal range of variance in the mileage, even with the same injectors.

Even professional test drivers do not get the same mileage on each test loop. Slight changes in the driver's attention, traffic, wind, air temperature, humidity and the degree of accuracy in measuring the fuel used effect the outcome.
A 5% minimum variance seems to be reasonable and that would be about 1MPG.

I suspect that to really know which injector gives the best mileage would requiring running each type of injector through several test loops to even out the variances. To really test something, you need to eliminate or cancel all variables except the one you are testing. Driving on public roads introduces millions of variables that can only be canceled by the averaging of many test runs.
Where are my old statistics books?

flip a coin...

at $2.50-$3.00 a gallon and +/- 1MPG difference your only losing fractions of a mile per dollar. unless your running a stroker or another high tolerance motor i see this test to be a waste of energy really. sell one set of injectors and call it a day brah.

What are the two different injectors your are using? What year vehicle?

There's no real way with the data you have to determine if there is a difference or not since you have a confounding variable in the traffic jams. Like lazyxj said, multiple trips with each injector will reduce the overall variation in your data and allow you to make a true comparison.

Talyn said:

What are the two different injectors your are using? What year vehicle?

Click to expand...

I'm trying the standard "upgrade" injectors. The 0 280 155 703 Neon ones and the 0 280 155 710 Ford "yellow stick" ones (with the 49psi FPR swap) since I sell them and people ask I want to be able to say I ran each and this is what I saw.

That neon one is pretty small for a 4.0L

I would watch the fuel trims and AFR to get some meaningful data.

To me MPG calculating is pointless, there are SOOOO many variables like temperature, wind, tire pressure, braking force, acceleration, weight(cargo), fuel from different stations etc. the only way you could really get a possible answer is if you used a moving road (like what the F1 teams have and go at an avg. highway, and city pace. pretty much trying to remove every possible variable.