New Insight owner - MPG concerns

[liebkid]

Hello everyone. Wow, what a great forum! I learned more in a couple of hours worth of reading here than months gathering info from everywhere else on the Insights!

After a year of indecision, a couple days ago I bought a 2000 Insight 5 speed with 35K miles. The car looks like showroom condition except it needs new tires soon. Driving from San Diego to Santa Barbara, I got a respectable 68MPG, on a very rainy day, which as my first trip, is not bad. One issue however aroused clearly. While the car accelerates preppy and its smooth during full throttles, it seems to continuously hesitate/ miss during cruising or while maintaining speed, at fairly low speeds (less than 40mph). It feels like a continuing engaging/disengaging of engine power that immediately goes away if I press the accelerator hard and rev up in cruising speed. I guess I'll be taking it in to my local Honda dealer but I was wondering if anyone here has heard of this problem and can venture at a guess of what it might be... the original owner of the car did all schedule maintenance up to 30K miles and babied the car inside out.

Also, as I need to change tires... would putting bigger tires (and maybe also thinner in width for less friction) improve freeway MPG at all?... theoretically the car will go further per each wheel rotation but due to the limited power of the small 1 liter engine, I am not sure if that will only cause me to have to press on the accelerator any harder or actually improve MPG a little bit!

Thanks for all your (invaluable) input

Michael
Santa Barbara, California
PS - Oh... I LOVE MY INSIGHT!!!!!!!!

[Insightful Trekker]

Hi liebkid and welcome to the forum.

The misfire / hesitation condition can be many things:

1) The normal NOx purge from regularly dropping out of lean burn.
2) EGR related, clean or replace. See:

EGR valve cleaning, instructions please
http://www.insightcentral.net/forum/vie ... php?t=1978

3) Or the worst with the greatest consequences (CAT damage) the primary O2(LAF) sensor going bad. See:

My 150,000km Insight Review
http://www.insightcentral.net/forum/vie ... 9&start=60

for one members extreme difficulty in finding a repair shop that knew what their doing. Testing a LAF type O2 sensor is an advanced knowledge task. Accurately diagnosing engine driveability problems such as your misfire can be a challange even for the most skilled mechanics.

There have been a couple other sporadic problems too. One member reported loose spark plugs (most likely improperly tightened after removal). Another had coil pack failures. See:

Forever... engine vibration
http://www.insightcentral.net/forum/vie ... php?t=4150

The main engine ground points tend to corrode in part due to the dissimilar metals and galvanic corrosion. When they totally fail you'll be walking, but as you approach this point all sorts of unusual drivability problems can develop. See:

Ground Cables Connection Mod
http://www.insightcentral.net/forum/vie ... php?t=3196

In regard to tires, any tire not closely matched to the same rev/mile as the OEM's will cause an additional error factor in both the odometer and MPG indicator. One member and moderator got together and did a comprehensive test in regard to one non OEM brand tire and MPG The loss was reported to be 12% See:

Tire Comparison Test
http://www.insightcentral.net/forum/vie ... 38&start=0

HTH!

[Dougie]

The stock tires are lighter (less rubber => less hysteresis loss) and can run at higher pressure than regular tires. Also they're pretty cheap. If you car about MPG, they're the best bet available--so far at least.