Age deterioration and loss in MPG

[Jivko57]

Hi , Several members are mentioning decrease in MPG with the aging of their insights. I had the same problem , I bought a 2000 mt in Nov '09 with 52.1 life time average on over 196k miles. The MPG a got gravitated around 52-54 and the engine was weak . LB was rare occasion and the car was not drivable in 5th gear due to lack of power.

In the next several months thanks to the helpful posts in this forum I made some changes, higher tire pressure, spark plug and air filter change, synthetic oil , egr valve change , egr plate cleaning, replacing the 12 v battery . This together with the summer mpg improvement has brought my average MPG to ~ 72-74...and still improving.

I had the valves adjusted in the repair shop, however the mechanic told me they were adjusted anyway

the next step is attaching new under body panels as previous ones
were gone by the time I was buying the car in November.

The inner fenders and the plastic bulkheads were in bad shape so i ordered new ones and replaced them.

I do not know what will be the effect on the MPG but suspect it want be much change since I drive slowly and rarely go above 55 mph.

but i am running out of ideas on what should i do after that to restore the engine power to close to new condition and to bring back the mpg to its best levels.

one possibility would be build up on the edges of the valves in the cylinder head which in turn lead to loss of compression , it would be great if somebody has been through such experience and can give some advise how this can be fixed.

another possibility is that due to engine wear in the cylinders and therefore increased gaps between the piston rings and worn out cylinder the engine is loosing compression and the productivity decreases.

what was the measured compression in a new insight 1 engine.

also any quantitative although approximate measurements of engine effectiveness are welcome.

for Example right lane cruiser advised he can max out the instantaneous mpg bar reader at 33-37 mph in 5th gear on level road.

I tried to reproduce that in my insight but best I got to was 125mpg @35mph on a level road in a perfect day (no wind , temperature in high 70s)

on another hand i managed to max it at 31mph in 4th gear.

so I suspect at present my insight is still at least 15 % less effective than it was when in its prime.

I hope with some help from the more experienced here to get some of this power and efficiency back...

thanks
jivko

[02insight]

how is your 144v battery? Some members have reported higher MPG's after a refreshed pack, or maybe you can try building a Grid-Charger to try to refresh it is its really old.

a new insight was rated for 70mpg, and that was probably with normal Honda oil, normal tire PSI, and probably no Hypermiling techniques except driving 55-60mph on the freeway.

We compensate for the engine wear by pumping up the tires, synthetic oils, extreme hypermiling etc...

My insight has 180k miles and the max at 35mph I can do is also 125mpg.

[nayrhyno]

Originally Posted by 02insight

...with normal Honda oil...

This is currently being discussed in another thread (Which Wt Motor Oil In My New 04 CVT), but the factory fill in the insight is a 0w-20 synthetic oil.


Related to the OP: What tire pressure at 125mpg and 35 mph? A few extra PSI could make the difference. Once you get that high every tiny thing makes a huge difference. Check your brakes for drag, ensure the road is level and speed accurate (GPS). Maybe the reference test was not totally level or wind free also...

[Jivko57]

The battery pack is ok, however I am getting a charger and will balance it on regular basis. But you may have hit a nail. Only the 12v battery change improved the efficiency so much , it is fully possible that a loss of power has started in the ima pack , and some of the engine power goes to constant charge.

on two hot days this month my SOC showed several bars less after the car stayed
all day at the parking lot at work. It could be the IMA is loosing power fast. Or it could be that due to the heat and temperature in high 80ties the car got too hot and the IMA fans were working trying to bring the pack back to more normal temperatures...

the tires are at about 52 psi now. I can increase a bit the pressure ,but would not expect a big change. Will see what will be the effect of the under body panels once installed.

One good thing that came to mind regarding engine wear, after reading the above mentioned thread: at 215k miles I do ot have oil consumption yet. with 0w-20. It means i can take of the list the possibility for significant engine wear in the pistons and cylinders...

[Right Lane Cruiser]

I've managed the 150mpg trick in 5th at 37mph in temps as low as 55F with very slight inclines (meaning, driving slightly uphill). I do run my tires significantly higher than most but it is very important to run the correct tires. Anything other than the original spec RE92s will cause a very noticeable loss in mileage.

I just rolled over 100K mi this morning and arrived at work showing 103.1mpg over 22.6mi... through some pretty heavy rain.

How high are you getting your state of charge? I see a pretty good drop in numbers when the charge drops from 19 to 18 bars. If you ran the level road test at 18 bars and got 125mpg you could see 140+mpg with 19 bars -- the car is quite sensitive to many factors when driven at its mileage limits.

[red1dr]

Maybe check the alignment? The Insight-I has special alignment settings (zero toe I think) that alignment shops might not know about. Maybe it was aligned to typical numbers somewhere along the way?? Toe helps the steering to self-center but it also causes drag.

An mpg of 52.1 when you bought it suggests that the previous owner drove it fairly hard.

[Jivko57]

Originally Posted by red1dr

Maybe check the alignment? The Insight-I has special alignment settings (zero toe I think) that alignment shops might not know about. Maybe it was aligned to typical numbers somewhere along the way?? Toe helps the steering to self-center but it also causes drag.

An mpg of 52.1 when you bought it suggests that the previous owner drove it fairly hard.

thanks, that is a good idea, never had the alignment checked so far. do you think Sears Auto will have the correct info or should i pay some more at the dealer but to be sure it is done right?

Re the previous owner, I Think he drove it ok, but with age the EGR valve was gone, the EGR plate was 85% clogged, and the 12 v battery was dead,
so all these things added up to ~ 10 -15 mpg hit.

After i bought it i was driving it for MPG, did my best in any hypermiling technique I could find and best was about 57 mpg on a tank. (with ~48 mph average speed on the highway)

And first half of November was not so bad weatherwise.

yesterday I got 90mpg on my 55 mile round trip to the job and back 90% highway with a little higher average speed.

I know am on the right track , just not sure of what the next steps would be.

[Jivko57]

Originally Posted by Right Lane Cruiser

I've managed the 150mpg trick in 5th at 37mph in temps as low as 55F with very slight inclines (meaning, driving slightly uphill). I do run my tires significantly higher than most but it is very important to run the correct tires. Anything other than the original spec RE92s will cause a very noticeable loss in mileage.

I just rolled over 100K mi this morning and arrived at work showing 103.1mpg over 22.6mi... through some pretty heavy rain.

How high are you getting your state of charge? I see a pretty good drop in numbers when the charge drops from 19 to 18 bars. If you ran the level road test at 18 bars and got 125mpg you could see 140+mpg with 19 bars -- the car is quite sensitive to many factors when driven at its mileage limits.

Thanks Right Lane cruiser,
yes my SOC was a couple of bars below the full, it just so happens this level stretch I am using for this simple test is close to my job and i always arrive there with several bars less than full, also I noticed it is very hard for me to reach the full charge as even wen is full the car takes a lot of more charge until it stops charging on coasting or regen breaking.

Today I will take some MPG hit and will force charge it just before i get to that spot and will check what will it be with full charge.

thanks for the idea. I Did not think of that.

[Insightful Trekker]

Originally Posted by Jivko57

yesterday I got 90mpg on my 55 mile round trip to the job and back 90% highway with a little higher average speed.

I know am on the right track , just not sure of what the next steps would be.

Huh!?

Did you miss your posted MPG numbers? Your now in the _hyper_ MPG "club". Is higher possible? Maybe, but don't even blink at the wrong time while driving or you'll suffer an MPG loss.

Given your numbers I doubt that the wheel alignment is off by much, if any. An alignment specialty shop would be much preferred over any National chain store.

Premimum fuels will help _slightly_ in this MPG range. AVOID all alcohol added fuels, less "bang" (MPG) per gallon due to the alcohol.


By my read your next step up the ladder is carefully choosing a route that is downhill both ways, with tailwinds only.

HTH!

[Jivko57]

Thank you Insightful trekker, it is a good score but mostly is because the weather is very good lately, and with the gas price so low probably the stations have gone to 100% gasoline as the ethanol probably is more expensive than thje gas right now...

i would wait and to see a couple of tanks with 80mpg or higher before i could tell for sure that this is not just a lucky one time strike...

thank you for the warm words and support!