I have an 05 6MT. Right now, I'm getting right around 12.5 combine mpg. And the thing is, that was during my test when I tried to get the BEST mpg possible. That means rarely shifting above 2200 rpms. Never gassing it. Always driving at 1500. That is not how I drive. If I was to drive normally and do the test, I would probably be getting 9.5 mpg. What's the explanation for this?
Thanks

 

Winter fuels have additives that help start in cold weather, the downside to that is milage is reduced 10-15%

 

Did you calculate the MPG by recording miles traveled and dividing by the # gallons you put in? Also any mods done? Maintenance? Even 12mpg is horrible

 

Yup. Thats how I calculated it. First I did 8 gallons and went to empty. I traveled 100 miles. Then I put in 5 gallons and traveled 60 miles. No mods. I do maintain my vehicle.

 

I thought my 17 MPG was bad...😜

 

Thats not really an accurate way to do it, next time fill it completely full and start recording the mileage. Next time you fill up fill it completely full again and divide the mileage.

 

The thing is, that is going to take a while for me. And within that period, I feel like I will floor it at least once haha. I can't help it sometimes. And then depletes your gas. But I guess I will try. To be honest, I don't see why it makes a difference from the way I did it?

 

it makes a difference because you don't know how much fuel was left in your tank from the previous fill up.

Usually we get "empty' light with 3 gallons still in our tanks.

Fill up the tank, drive till empty, fill up again. Note the amount of gallons that you filled up the second time. Tank is 20 gallons, so if you fill up only 17 calculate your millage based on 17 gallons.


There are alllllllllllllllot of reasons why your car gets bad fuel millage, all of them have to do with maintenance. Spark plugs, air filter, tire pressure, engine oil, transmission oil, rear diff oil, wheel and tire size, your weight. There's just endless amount of factors that will effect your fuel economy.
With proper maintenance and attention to main factors you should be easily getting 18-19.
My average is 20-21 city and 25 highway.

 

Why do you say fill up the tank, drive till empty and then fill it up again? Why can't I just fill it once?

 

Depending where your tank is, you'll need to refill it twice so that your depletion from full is at close to the same point as possible. That's how I calculate mine as well.

 

you fill up the tank = you know it's full (20 galons)
drive till empty = you know the millage you drove, but how many gallons you used?
fill up again = gives you the amount of gallons you used

You need to fill up again to determine how many gallons were used to drive those miles.

 

+1 what the other guys said. Just saying "I drove till empty" is very subjective and you really don't know accurately how much gas was left. You need to fill it clear full then start from recording. when you fill up the next time fill it completely full again and you will know exactly how many gallons you used. Divide that into the # of miles traveled and you will have you real MPG.

When was the last time you replaced your spark plugs? if they're worn they can cause bad gas mileage, and untuned VQ's tend to wear through them pretty quick. Even stock setups.

 

I seriously doubt you're getting 12mpg, let alone 9.5. Calculate your MPG properly using the method described above. You don't always need to drive it to empty, what's more important is starting with a full tank and filling it when you pump again.

 

04 6mt, going from completely full to E and filling up 17 gallons each time. Completely filled and e about 7 times now I think it was, mixture of highway and city and im getting 220 miles per fill up. Just got an oil change, brand new throttle body, maf cleaned by dealership, car runs fine, no engine mods.

Calculating 220/17=12.94 and with mostly highway I got 240 once on 16.5 gallons. So 240/16.5=14.54

Driving style conservative, no extra weight in the car, I weigh 175lbs. Shifting at or below 2.5k rpms and mild accelerating. When sustaining a speed I keep it under 2k.

Ordering spark plugs, but I doubt its that. 70k miles.

 

I don't get it....I get over 400 miles out of every single tank. I am by no means light on my right pedal.