I don't check the mpg too often but sometime last year I was getting 34mpg highway. Just checked this weekend and it was 26mpg!! Anyone got an idea? No major maintenance to date on this vehicle, just regular oil changes and brake pads, 107K miles.

 

sure you filled it up all the way? lol. so many factors with this. have you been using your AC more often this year? no really low tire pressure?

since you're at 100k now but didn't do any major services or anything besides oil and brakes, i'd say you're ready for a basic tuneup. Look at getting new spark plugs, possibly wires also, clean out the throttle body/intake, change air filter, and maybe do a seafoam treatment before next oil change and run some in the tank to clean injectors a bit.

those are easy DIY things that may or may not help, but they're some basic things to do and at least might help narrow it down.

 

Haha, yeah, i'm pretty sure it was a full fill-up. I'm gonna check again this week.

Actually, i did do plugs and wires about 5K ago. I need to pull them and double check the gap, I think spec is 0.043" from this i found. Page EG-20.

 

just for follow-up... gapped the plugs, spec was 0.28-0.32. I did em around 0.31. MPG went straight back up to 34-36.

 

Glad it was something so simple.

 

I love my 1NZ!

 

yeah, great little car. still getting 32-34 mpg at 111K miles. how many miles does yours have? i was thinking of getting the timing chain but i think it's ok since it's a chain.... other than that it's had 0 problems.

 

just unloaded my 3dr yaris with 5 speed and it was decent. speed cut out at 117 but i sure surprised many a civic at them stoplights. cold air Intake/Header and catback exhaust made the difference....