Are all percent mpg increases based on a bad base??
 

O.K. I have my usual, tuned-up, mpg figured out. Now, I buy better brand of gas, a + 2 % increase in mpg; then I fill with premium for another + 2 % mpg; then put on magnets, correctly, for another + 5 %; then I put in a gas pill for another + 5 %; then put in a carb. toranado winder for another + 3 %; then I add liquid gas saver for another + 3 %; then put in 3 oz of acetone per 10 gal. for another + 10 % increase in mpg; then change spark plugs for another + 3 %; Then Spark plug wires for another + 2 %; Pump up the tires, to 60 lbs, for another + 1 %; us synthetic oil for another + 1 %; then drive slow for another + 1 %; etc, etc. This makes for a 38 % + increase in mpg??? If one kept on adding things...unload the trunk, etc one could easily get up to 50 % mpg gas savings. Can a vehicle that usually get 14 to 18mpg on road increase such to 21 to 27 mpg ??? The question is a percent increase from what base?...for sure not after one has a half dozen items already in the base figures that has already increase the mpg from the norm.

Using the stuff you mentioned, probably not. But using quantified stuff that works, yes, no sweat. Any percentage increase in based on where ever you start, so if you've already done half the things you can do, and start measuring improvements from there, then you'll see a smaller increase. A percentage is just meant to show the amount of change from one point to another, not an absolute figure.

I'm not sure I understand the question but yes you can make some pretty big increases in mileage just look at the top ten in the garage. You should only change one item at a time and see what effect that has on the mileage before you change something else. So if you're getting 25 mpg and increase tire pressure and the mileage goes to 26 mpg then that's a 4% increase. Then if you add duct tape to the trunk and get 28 mpg then that a 7.6% increase over the 26 mpg and so on and so on.

Welcome to the site.

Edit: what omgwtfbyobbq said

As mentioned above, do the tests one at a time to eliminate all those other confounds and then whatever actual, repeated value you get is the new base for the next test.

So in your example if all those gimmicks in your post were each worth those percent values, your result would actually be plus 44.9% increase not 38%.
(1.02)*(1.02)*(1.05)*(1.05)*(1.03)*(1.03)*(1.10)*( 1.03)*(1.02)*(1.01)*(1.01)*(1.01)

= 1.449 (original value plus 44.9%)

I think it's reasonable to get this gain, but it's more reasonable to expect you'll get the better part of that gain from changing driving habits.

Edit: haha zpiloto -- "Duct tape is only a crotch." indeed

but no one answered ....







does the duct tape color/pez dispenser need to color coordinated ?;)

OMQWPNASDQ, What are the quantified items that work...I am new here? Please & takks-a-lotta.

What you were talking about initially, mileage. You pick something to test, say a set of new LRR tires on a set of spare rims, find a route with minimal and consistent interruptions, and test your mileage w/ the new tires, then another run with the old, then another with the new, and maybe a few more alternating tests, in order to see if there were any consistent improvements. The difference between your mpg with the old and new tires can be expressed as an absolute, say a 1.5mpg increase, or a percentage, say a 8% increase. Expressing it as a percentage is useful for other drivers because they can perform the same mod, or a similar mod, with a vehicle that gets an average of more or less mpgs than yours does, and predict how much their mileage will increase with the same mod you did.

non of those magic pills work or anyouter gimmic really does anything. just try the slowing down and learning as much as you can about driveing technics and go from there. DONT BUY INTO ALL THAT CRAP!

It really depends on what is draiging the mileage on your vehicle down, if it's simply to large of an engine or to low of gearing then you might see less results from one set of ideas but good results by shifting sooner, but if your vehicle is simply out of tune, then you will see strong results from a basic tune up, just like if you have a vehicle with alot of airodinamic drage you will see results by adding a belly pan.
also, you can add your percentages two ways, let them compund or add them all together, then add them, if your base number is 14mpg, and compund them then you get 20.285 but if you add 38% to 14 then it's 19.32 or almost one mpg less.
just like doctors don't give a standard set of medication to make you feel better without asking about symptims, you shouldn't just start adding things to a vehicle without asking how they will help you acheave your end goal of making your vehicle function better.