07 HCH MPG issue due to tires

[HCHdriver]

Ok so here is may story a little background for me in a nutshell I have been a mechanic for 10 years a former Honda tech and currently a reserve officer and Hyundai tech.
So doing the part time police officer gig on the weekends I travel a lot so I decided to buy a 07 HCH.

After I got it I noticed it wasn’t getting very good mileage. I did some looking on the Internet and found the 33mpg horror stores on a few hybrid forums and I figured I just made a 16k dollar mistake. I had the battery dump issue and still do and the low SOC The terrible update had been performed before I bought it.
So to make a long story short I called Honda customer relations 2 times with no real answer and the first guy acted like he could care less about my car that is supposed to get 40+ in town that was actually getting 29 to 32 mpg in town.
The IMA battery stayed at 5 to 3 bars ALL the time never ever ever ever saw 6 bars much less 7 or 8 so I figured the IMA battery was toast or the nasty update was screwing it. 4 trips to the Honda dealer I worked at once upon a time with no real results other than the “we checked it no problems found “ routine I decided to do a little experiment.

I set out a 14.5-mile track though town that included some stop and go traffic and hills with some straight stretches too.

Here were the results
2010 new off the lot HCH 45.3 mpg
My 2007 HCH 32.6 MPG

After driving my HCH for 1000 + miles I was use to the way it drove I noticed a large difference in the way the 2 cars drove the 2011 felt like it just rolled better.
Going up hills it would charge the IMA id never see that in mine so my next experiment was to ask the dealer if they would swap wheels with me, they thought I was nuts but they did it for me.

The results were astonishing!
First run with my car I did the 14.5-mile track at 44.8 mpg with a lot of lunchtime traffic at 12:00 noon I could not believe the difference! The car just rolled better, after that I waited till 6 pm did it again with a whole lot less traffic 49.2-mpg holy crap! The IMA charge stays at 6+ bars now and rarely do I see 5 WOW!
Mainly because the car rolls better it charges the battery now. Still have the battery dump but it recharges fast.

I never thought in a million years tires would make such a difference the Yokohamas the dealer put on prior to selling the car were brand new but apparently the rolling resistance they have the poor HCH thought it went back and forth to work up hill both ways.
I now have Kumho eco Solus HM KR22 tires aired to 40 psi.
Tirerack.com labeled them as a Low Rolling Resistance tire so I got them after putting them on I went to their website and found that they are a 100k mile tire but not a true LLR tire that irritated me highly as well. I should have got the ecowing but still the mileage im getting is great compared to what it was.
Hope this info helps



Log showing mpg after tire change IS stands for Interstate H for Highway C for City



low mpg Yokohamas



New tires



Best I did

[Weather Spotter]

Good way of testing to find what was the issue

Would you please add you data to our wiki page about LLR tires : Low rolling resistance tires - EcoModder

Thanks!

[gtstanger01]

I got speeding ticket in Cape Girardeau many years ago lol.

[bwilson4web]

Do you still have the 'donut' spare?

It would be neat if you could get a full-size rim and mount one of the crappy tires as a full-size spare. Then if you have an IR temperature gauge, someday in the future, put the crappy tire on one rear wheel and do a test to measure the relative temperature differences.

For tires to cause a significant drag, there should be a temperature rise from the generated heat. . . . I'm not defending the Yokos but just suggesting a way to quantify the difference.

Bob Wilson

[arcosine]

A guy a work had a Honda hybrid, Accord I think with a CVT, he bought it new. He often commented on his dissatisfaction. it got worse mileage than my saturn. He finally sold it.