A little background of my car. It's an 99 GS with 172K miles and the last tuned up was two years ago.

When my car used to have low mileage, I often used the STP gas treatment every other time when I filled up my car. I was getting 290+ miles per gas tank then. I haven't used the STP for two years now because someone told me it was pointless. Anyway, as we all know for the past year, gas prices has gone up like a rocket and so it got my attention of wondering why I have been getting low mileage per tank lately. I drive to school that is about 25 miles away at an average driving speed of 75 MPH everyday.

So two days ago, I used the STP gas treatment again and drive to school at an average of 65 MPH to see if that save any gas. So far, I have gotten 80 miles with my gas needle pointing a little over 1/4 of the gas meter. Usually at this point, I get about 55-60 miles. So if I were to keep this up, I should be looking at 300+ per tank even without tuning up the car. I bet if I do the tune up, I will get better gas mileage. Just wanted to share and by the way, driving 65 MPH took me 3-5 minutes longer to get home. It is definitely worth driving a little bit slower because if I am getting 70-80 miles more per tanks, that means I am saving about $10 on each fill up.

 

That gas treatment didn't do crap it was the reduced speed that is getting you better gas mileage. And for $1-2 per gas treatment your just wasting your money. Drive slower, make sure the car is properly tuned, remove unecessary weight and make sure the tires are properly inflated.

And if you're only getting 300 miles per tank, then that is pretty crappy gas mileage, I can get around 330-350 miles per 10-11 gallons.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by suken19 &raquo;</TD></TR><TR><TD CLASS="quote">A little background of my car. It's an 99 GS with 172K miles and the last tuned up was two years ago.

When my car used to have low mileage, I often used the STP gas treatment every other time when I filled up my car. I was getting 290+ miles per gas tank then. I haven't used the STP for two years now because someone told me it was pointless. Anyway, as we all know for the past year, gas prices has gone up like a rocket and so it got my attention of wondering why I have been getting low mileage per tank lately. I drive to school that is about 25 miles away at an average driving speed of 75 MPH everyday.

So two days ago, I used the STP gas treatment again and drive to school at an average of 65 MPH to see if that save any gas. So far, I have gotten 80 miles with my gas needle pointing a little over 1/4 of the gas meter. Usually at this point, I get about 55-60 miles. So if I were to keep this up, I should be looking at 300+ per tank even without tuning up the car. I bet if I do the tune up, I will get better gas mileage. Just wanted to share and by the way, driving 65 MPH took me 3-5 minutes longer to get home. It is definitely worth driving a little bit slower because if I am getting 70-80 miles more per tanks, that means I am saving about $10 on each fill up. </TD></TR></TABLE>

that is main reason why you're saving gas...if you want to clean injectors use seafoam

 

slower driving = better gas mileage

ditch the treatment

 

The first half of my tank reads slower then my second half, as in my car shows something like 50 miles and it barely even moves, it usually evens out at around 150,160 at half tho.

Use cruise control if you can, here in Socal it's kind of hard due to the traffic, but once I get off of work at night the traffic is less packed in. Except for that occasional a*****e in a G35/M3/TSX, who always zooms up on you in the slow lane going 80+ and flashes his headlights at you

 

On top of what has already been said, the gas gauges are NOT accurate. Don't go by what it says. Also, "Miles Per Tank" figures mean nothing. Figure out the "Miles Per GALLON" you're getting (wiki it, if you don't know how).

 

most efficient speed for driving ranges from 35mpg to 45 mph. I read that in one of those "hyper driving" type articles where they tell you the crazy **** people do to save gas, like turning the car off while driving... Which locks your steering wheel...