2000 Accord EX - giving only 25MPG :-{

My 2000 Accord EX, 5-Spd, 55K, Boston, used to give 30-32MPG. Suddenly
this winter I noticed that it is giving only 25MPG. Can someone tell
what could be the reason. I do regular oil changes and nothing else, so
far. Please advise.

 

I have an 04 EX with 42,000 miles and I also noticed this winter that
my mileage dropped from about 33 MPG (half city/half highway) to about
29. I figured it was the harsh cold/weather in the Philly area that I
live and drive in. I am waiting to see what spring/summer has in store.

 

That is quite a drop. The oxygenated fuel mandated in many areas during
the winter will reduce gas mileage noticeably, 5 - 10% according to
sources like www.chevron.com. Cold weather will reduce mileage as well,
even more so if you are making many short trips.

 

Here in California, I noticed a 20% drop in mileage with the oxygenated
fuel. I commuted to work in a Toyota p/u and got 5, 70 mi trips per
tank. After the state mandated the 'NEW' fuel, that dropped to 4. U.C.
California said that the drop was only 6%. You do the math!

Randy

 

Without actual mileage numbers and actual fuel used we can't do the math.
How many gallons of gas were left in the tank before and after the fuel
change before filling up?

Did you take 13 gallons to top the tank after 5 trips before the change and
11 gallons to top the tank after 4 trips after the change?

Mileage is computed by taking the miles driven since last fill up and
dividing by the number of gallons to refill. Not by approximating how many
"70 mile trips" before the needle left me believing I couldn't do one more
trip before filling up. Heck, each on of those weeks of trips could have
had a different number of trips to the grocery store in between fill-ups
that would have also skewed the numbers.

 

The math is simple. the tank doesn't change in size. When the gauge
reads empty it's empty. I always refueled at the same point. 5 trips
down to 4 is 20%.

 

So it stalled? Everytime? Exact same number of litres in each fillup?
Wow!

Only those trips? Nothing else? Same weather too?
Wow.

 

It's really empty? You stalled and had to be towed to the gas station?

How much is left in the tank at each fillup does change in size. Your
method of computing gas mileage is about as accurate as having the waiter
read your tea leaves to determine the check.

Today when I filled up, the car took 14.7 gallons. The odometer indicated
that it has been 347 miles since my last fillup. Now we have some math to
do. That works out to 23.6 miles per gallon. Do that a few times in a row
to get a better/consistent winter average. Do the same in the summer. Now
you have a comparison.

Your method does nothing to compensate for how much actual gas was used.
One fillup maybe 12 gallons used, another 13, the next 11. Your also
counting just "trips to work of x miles". While it's possible that you
don't use your vehicle for anything other than commuting to work, it's more
likely that you sometimes hit the grocery store, drive out at lunch time,
run an occasional errand.