Horrible gas mileage

Question

Good morning Scotty, hope you’re doing well! I am from Quebec, Canada and I bought an automatic transmission 2000 Acura EL (1.6L vtec engine) a year ago. It has now certified 83000 km (about 54 000 miles). I will translate everything into the american metric system. My car, which made about 35 mpg last summer, is now making around 21 mpg and sometimes it’s worse than that. Both measures were made in conditions where i did 65% city and 35% highway, and my gas mileage has been going worse and worse since the beginning of winter. My tire pressure is good, my spark plugs are brand new, I changed my air filter and my winter tires are in a good shape.Take care and have a good day! 🙂

Mod_Man · Accepted Answer

Couple of things I would do:

1. Check the air filter to make sure it is clean

2. Check the fuel filter to make sure it isnt clogged

3. Run a bottle of fuel injector cleaner through the tank

4. Clean the MAF sensor and throttle body

That's where I would start. All are easy to do yourself. 🙂

2000greenAcura · Answer

i’ll try that! Thanks a lot

geriscan · Answer

Enhanced Diagnostics/Live Data information would be helpful, for example, in looking at short term and long term fuel use. (Blue Driver has this information for many vehicles). So, a scan is ideal.

I'm thinking that you might have an intake or exhaust leak. The car gets more air than it needs, the computer adds fuel, the car runs too rich, and efficiency is reduced. Scotty has a "cigar smoke" test for finding intake and exhaust leaks. (The fuel trim data would confirm this, if it is the case. Anything over 10 percent, plus or minus, is excessive).

One way you can tell whether this is the case is to swipe your finger across the inside of the tailpipe. If it's black and sooty, you're running too rich, burning oil.

And, yes, do all those things that Mod_Man suggested, above.