You can be more accurate than an app, that's why.

 

??? math is math.

 

How exactly can I be more accurate than an app? I input mileage and number of gallons and it does the exact same calculation that I would have done manually. Then it uses that data to show me all kinds of stats. When I input mileage down to the exact mile and gallons down to the thousandth of a gallon, I don't know of any way of being more accurate than that.

 

Since it allows you to add the full info, I'm sure it will be accurate enough. In that case, better get back to figuring out what's not right with your car. Good luck.

Did you determine whether or not the fuel was replaced with ethanol or had already been done or not? That may be the entire problem and if so, you can't really fix it unless you can find more regular fuel.

 

I get gas at the same 3 or 4 stations around my area. Nothing has changed about my habits the gas, or the car, that I know of. The mileage just drops by 3 mpg once per year.

 

The pumps should have a sticker on them to tell you what the fuel contains, like "at least 10% ethanol" or "no more than 10% ethanol" and "gasoline" or "E85" and if you don't already know which, look for that and if it is, look for pure gasoline. If you can afford that(it's expensive if ethanol/gas is standard fare), you'll get much better mileage using that.

 

I'm not sure what could be wrong with it, but my girlfriends car is an 02 1.7 auto civic that has been beat to hell and has 211000 miles on it now. Even with a failing headgasket, it still always delivered 35-40 mpg. We just took a trip to Wisconsin and it did 43 mpg, so I don't think age is the issue. The spark plugs are 100,000 mile service interval, so those could be original plugs, which might cause an issue. Also, if its an auto, the lockup converter might not be working for some reason or another. When the ect went on ours the lockup wouldn't work and it was closer to 30 mpg. Maybe the fuel pressure regulator or the O2? Sorry I can't be more help, we've never really had an issue with the car(save for the headgasket).

 

Yes, they've all had 10% ethanol around here for years. That hasn't changed.

 

Thanks for sharing your experience. Could you tell me more about your ect experience?

 

my 2.0 auto rsx with 174k gets 28-32 mpg religously...28 in the cold months and up to 32 in summer with no a/c on.

air filter, pcv valve, o2 sensors.

What weight oil are you using. I used 5w30 in the rsx up till recently and started to use 5w20 again and I think she has picked up some MPG. Are you running the a/c more?

 

Btw, you are saying it's dropping more each yr and not rising at any point, just decreasing each year, correct? That's how it looks, but if it's coming back later, that could be attributed directly to the winter blend vs summer blend.

 

Correct, the last two Falls it dropped around 3 mpg each time, then stayed steady (at that lower level) for the year until the next Fall, when it dropped again. It coincided with having the car inspected.

 

Have you tried anything that has been suggested?

 

The MPGs in every vehicle I own drops very noticibly during the winter months. Mostly from idling longer or the winter blend fuels. My diesel barely tops 12 MPG city during the winter from idleing and winter blend fuel. I see 17 all day during the summer.

 

I used to have a 95 civic about 10 years ago and got around 27-30 MPG with my regular driving having already done cap, rotor button, fuel filter, spark plugs (ALWAYS use NGK plugs in a Honda, they just run better) and wires, but when I had my headers installed on it they guy couldn't get the o2 sensor out of the stock manifold to install into the headers so he went and bought one from a junk yard because he said the ones at the parts stores cost so much (then he charged me for it, with out making sure this was OK by me first, just another reason I don't like that shop) eventually I decided to do 3 things, I replaced that crappy o2 sensor with a new Bosch universal one that literally took 10 minutes to wire up and was CHEAPER then what the guy charged me for the used one and reverted back from my 17's to my stock wheels and tires (since I was driving several hundred miles to Orlando for vacation and didn't wanna put those miles on the more expensive tires and had the front end aligned by an "old school" guy (no computerized machine) BEST ALIGNMENT EVER and cheapest too, when driving down the Florida turnpike well after midnight I started in the left lane set my cruise control and let go of the steering wheel I drove an ENTIRE MILE @ 70MPH before the car had drifted to the far end of the right lane and I had to take the wheel again. I got 35+ MPG on that drive down and coming back I had my sister and her friend along with all there crap in the car and still got 29 MPG driving home.

Sum it up, do a full tuneup if for no other reason then to do it, it's so easy on those cars, especially compared to doing plugs on an f-body.