STP and gas mileage
scuba14c, Wed Jul 12 2006, 01:07AMI have a 1997 Chevy blazer. When I got it, it came with 2 bottles of STP additive. I added it over a long distance trip and got 25.9 mpg. With out it, the mileage is 21 mpg. The way it was measured was through an onboard calculator. Is this just a fluke, or does this stuff actually help?
Re: STP and gas mileage
Desmogod, Wed Jul 12 2006, 03:24AM
I would be dubious of any MPG figures not collected in a scientific manner.
The variables are just way too large.
Desmogod, Wed Jul 12 2006, 03:24AM
I would be dubious of any MPG figures not collected in a scientific manner.
The variables are just way too large.
Re: STP and gas mileage
cbfull, Sat Aug 05 2006, 10:45AM
The first thing that comes to mind is the onboard calculator. What measurements does it use to determine MPG?
I was involved in a very in-depth discussion about improving your MPG in another thread. This one was mostly focused on whether or not adding acetone can damage the fuel system. The other issue was trying to understand how such a small concentration of acetone in your gas can make a measurable difference.
In response to your question, you need to make sure you get your gas from the same station every time because the fuels are more different than you think. So far my biggest boost came from when I chose a different gas station, and assumed that since they are both m8b!L3 gas, it would make no difference. What I immediately found was that I consistently got a tank of gas to make it over 300 miles each time before filling up, and the previous location was only getting my trip counter to about 250ish. That is a VERY significant difference. I am baffled as to why two different locations of the same name would have such different gas quality. It almost makes me suspicious of them.
Can you find the ingredients on the bottle of STP and post them? I think that stuff uses a mixture of toluene, acetone, xylene and some other hydrocarbons. Not sure though.
cbfull, Sat Aug 05 2006, 10:45AM
The first thing that comes to mind is the onboard calculator. What measurements does it use to determine MPG?
I was involved in a very in-depth discussion about improving your MPG in another thread. This one was mostly focused on whether or not adding acetone can damage the fuel system. The other issue was trying to understand how such a small concentration of acetone in your gas can make a measurable difference.
In response to your question, you need to make sure you get your gas from the same station every time because the fuels are more different than you think. So far my biggest boost came from when I chose a different gas station, and assumed that since they are both m8b!L3 gas, it would make no difference. What I immediately found was that I consistently got a tank of gas to make it over 300 miles each time before filling up, and the previous location was only getting my trip counter to about 250ish. That is a VERY significant difference. I am baffled as to why two different locations of the same name would have such different gas quality. It almost makes me suspicious of them.
Can you find the ingredients on the bottle of STP and post them? I think that stuff uses a mixture of toluene, acetone, xylene and some other hydrocarbons. Not sure though.
Re: STP and gas mileage
..., Sat Aug 05 2006, 08:22PM
I would just assume that the stp did its job and cleaned out your engine, increasing your cas mileage...
Any number of maintenance things can do that, replacing the O2 sensors (all 4 of them at $80 a piece
) and air filter in my moms car got about 15% gas mileage than before 
..., Sat Aug 05 2006, 08:22PM
I would just assume that the stp did its job and cleaned out your engine, increasing your cas mileage...
Any number of maintenance things can do that, replacing the O2 sensors (all 4 of them at $80 a piece
) and air filter in my moms car got about 15% gas mileage than before Re: STP and gas mileage
muciek man, Sun Aug 06 2006, 11:27PM
one thing i did to increase millage in my truck was remove the egr valve and put it in an ultasonic parts cleaner with some silvent as replacing it is almost $100
i decided to try that first and improved about 3 mpg this is a real pain though as it is part of the vacum system of the car it is easy to puncture the diaphram inside unless your careful but if you can do it it helps
muciek man, Sun Aug 06 2006, 11:27PM
one thing i did to increase millage in my truck was remove the egr valve and put it in an ultasonic parts cleaner with some silvent as replacing it is almost $100
i decided to try that first and improved about 3 mpg this is a real pain though as it is part of the vacum system of the car it is easy to puncture the diaphram inside unless your careful but if you can do it it helpsPrint this page