Bought a 2005 Honda Insight on my 18th birthday and MPG is low?

[ethicaldesign]

On my 18th birthday I got a car loan and flew one way from PA to North Carolina. I bought the car and drove it 8.5 hours to PA. This was on Saturday. Now it is Monday and over all my average MPG is only around 45MPG. I don't speed nor do I have a lead foot. I have checked the tire pressure when I bought it and all tires were 30 and under. I pumped them up to 38 in the front and 35 in the back. This didn't change anything. I do not have the bridgestone tires on it. It has sumimoto tires. The insight is an automatic with 100,000 miles on it. I am a sensitive driver and have tried numerously to achieve lean burn mode. Is there a video tutorial explaining it? Is there something wrong with my car? It is great exterior and interior condition. Please help...?

[Eli]

First, get rid of the non-OEM tires and if you can't do that right away, pump them up to at least ~45PSI. When you do get the Bridgestones, run them as high as you feel comfortable, 45PSI minimum IMO. Many people run 50-60PSI. I run mine at 50PSI.

Second.. I hate to be a harbinger of bad news, but the automatic Insight does not have lean burn. That's why the manual transmission versions are both more desirable and capable of getting higher fuel economy.

Are you using the A/C? That will cost you 5-8MPG+.

It sounds like the tires are probably the biggest problem, assuming the car is mechanically sound. No error codes?

What speeds were you traveling?

[freezin4]

Hi and congrats on your purchase.

Did you buy the one in Wilmington?

Unfortunately, the CVT model does not have the lean-burn capability. Your car is however a SULEV, which pollutes even less than the 5 speed.

The non-OEM tires will account for some MPG degradation for sure. And with the CVT, you will not be getting 70 or 80 MPGs consistently like some of the experienced drivers in a 5 speed model may. I do have a 5 speed and I average 57-67 MPG (for the year). Better in summer, and on the lower end in the cold weather. I keep my tires at 50 psi.

Ensure you have the under body panels in place. Absence of these will hurt MPG.

Also be sure you have the 0W20 oil in your crank case and only 2.5 quarts of it. Do a search on CVT Trans fluid change, and consider doing that as well.

Recommend you read the "Encyclopedia" and "Knowledge Base" sections. Links are on home page. You will learn a great deal more about your special car.

All the best, and congrats again!

[ethicaldesign]

Thank you both for your quick response. I'm afraid that pumping my tires to that high of a PSI will run me at risk for blowing a tire. When I check my oil, I have much more than I should. If I were to purchase the OEM tires, how much of difference can you predict it will make? The tires that are on it are pretty much new. There are no signs of use really at all. Will OEM tires be expensive? Thanks!

[Eli]

Do whatever you feel comfortable with of course, but be aware that max sidewall on the Bridgestone tires is 45PSI. That's the minimum you should run, IMO. Like I said, many people run 50 and as high as 60PSI.

Ugh........ Freaking idiots! This is why I do all my own work. Get the excess oil out of there immediately, and make sure the proper oil and quantity is put in. How far over the Full line is it? If it's only a couple of millimeters, don't feel rushed. If it's way over the line, do not drive it like that as you risk blown seals.

The bridgestone tires can make a profound difference. It's difficult to say, but you could see up to +10MPG with them depending on how crappy your current tires are. Does it have the OEM wheels?

A new set of bridgestones will run you around 500 bucks.

What kind of MPG are you expecting from the car? Also, you never answered - were you using your A/C on the drive home, and how fast were you traveling?

[ethicaldesign]

I was traveling around 70MPH as an average because some of the speed limits went up to 75 and as low as 55. I used the A/C the entire time. I bought the car from Raleigh, NC.

I'm expecting around 65MPG..

[ethicaldesign]

Originally Posted by ethicaldesign

I was traveling around 70MPH as an average because some of the speed limits went up to 75 and as low as 55. I used the A/C the entire time. I bought the car from Raleigh, NC.

I'm expecting around 65MPG..

It is about a 1/2 inch over...

[Eli]

That explains everything.

70MPH, A/C and wrong, underinflated tires = 45MPG in a CVT.

Slow down to 55MPH, turn the A/C off and get the proper tires(at least inflate to 40psi....), and that number will likely come up to ~60-70MPG.

Originally Posted by ethicaldesign

It is about a 1/2 inch over...

Ugh, yeah, don't drive it like that. At the very least drain some of that out, but it would be better to put 0W-20 in it so you know whats in it.

[freezin4]

Concur with Eli.

I would think 10% improvement of MPG with OEM tires.

There have been blow-outs with sidewall failures of the Potenza tires. (there are some pics on IC) Like I said, I run 50 psi.

New Potenza RE92s run about $85 a piece, plus shipping. Local tire shop may be able to get it installed for you for $100 a piece.

Read the owner's manual and be sure you understand the climate control functions.

Good luck.

[Eli]

Are you going to be changing the oil yourself, or using a place like Jiffy Lube? They're likely the reason your oil is overfilled in the first place.

I went to Jiffy Lube ONCE because I was in a rush, about to drive 1400 miles and wanted to change my oil before the trip.

They overfilled my car by at least a quart(which thankfully I checked before I left), AND they stripped the threads in my oil pan(which unfortunately I didn't realize until the next oil change). I was so furious, and vowed never to use any such place again, ever.

Be careful, the world out there is extremely unfamiliar with our cars. That includes Honda dealerships.