I have constantly been getting MPG in the 50's at minimum until last week. Now I am in the 40's. Took my insight to the dealer and they changed the oil and air filter and stated that they could not find anything wrong. I had the battery and the computers replaced last October and everything has been fine since. I have reset the computer and added a gas additive to try to fix the problem but the MPG is still horrible. No computer check list or IMA light. Any ideas? The dealer told me today they could find nothing wrong but something is. They told me today that it could be the new gas mixtures but I think thats a load of bull.

 

Is your Insight a stick shift or CVT?

That will give us an idea just how severe your MPG problems are.

Has the weather changed dramatically, like lots of rain & cooler? That will kill your fuel economy.

Checked your tire pressure lately? I know it's a common sense thing, but I must ask.

Did you make a tire change recently - to something other than RE-92's?

Why put an additive in the fuel? Is the engine behaving strange? Misses or stumbles?

Have you verified that the dealer did not over-fill the crankcase?

And finally - How's your driving?
A quote from you in a previous post :
"I run the hell out of my little car as my job keeps me traveling around the state."
Does that mean aggressive driving or just a bunch of miles?

Some possibilities to check:
1.) Bad O2 sensor
2.) EGR valve
3.) Tire alignment

Good Luck to you.

 

The type of driving will be very informative. I've gotten 95mpg under ideal highway conditions, but 40mpg could be normal if it's a very short trip on an iced road.

Sounds like your Insight is new, but if not, the lifetime mpg could hint on the treatment before you got the keys.

 

I have a 2000 model and its a manuel. Tires have been on for a year. No other indications of problems. My average city driving is about 55 mpg. Now its about41 mpg since last week.

 

Again, we need a bit more info, so I'll reiterate some of the earlier questions so we can help you.

What region of the country you are in? Last week was colder than usual in many parts of the country. (25 degrees below normal last week in Wisconsin, plus I even saw snow!!)

What brand tires are you running? Are they the original equipment Low rolling resistance RE92s?

What's your tire pressure?

 

Hi jd,

Cold weather and low tire pressure not to mention stop signs and hills are very rough on gas mileage. Some combination of them account for your problem. If your tires are anything other than the OEM Potenzas you can pretty much count on a mileage hit. Last time I had my Insight serviced at Honda the monkeys reset my tire pressure to 32psi! (I usually keep them around 42.)

A 2000 model could be having recalibration issues…

T