isam250

iTrader: (7)

I had the car at 44k and changed to synthetic 5-20 and i averaged about 380-390 from full to empty. did the recall for the vvt-t actuator and it went down to 375-380 not too much. then i recently changed the differential fluid and spark plug. on start up i had miss fire in cylinder 5 when we scanned the car p0305. turns out the spark plug was touching and gapped it to the spec, everything was fine.i went to fill up and it dropped to 350 per tank. i mostly do high way driving and i average about 26-27 range. my question is what can cause the bad gas milages?

XxGoKoUxX

You may need to regap all of them correctly.

Sometimes upon reinstallation you tap the tip against the sidewall and it misgaps the spark plugs. I know for the 3UZ, the spark plugs on the driver side are a PITA and that happens often .

Which spark plugs did you purchase? I'd stick with the Denso Iridiums (long life if you want less mantainance, performance if you don't care and don't mind changing every 30-40k mi).

There's also the fact you filled up on bad gas. Not really bad, but gas that's not as high quality as another. If you filled up at the same station, then ignore this point.

you've lost 5-10 miles, I would say that's not too bad. Have you considered the weather into the equation also? Starting up the car and letting it sit a bit longer than usual might have compensated for the extra gas loss.

isam250

iTrader: (7)

Let's see what happens after the 2nd fill up.