Honda Insight w/Acura TSX engine - Ecomodding

[serialk11r]

I would imagine that on a car as light as the Insight, the difference in price is going to be bigger than the difference in rolling resistance (though with the amount of distance you drive, wear is also a factor).

[MetroMPG]

Originally Posted by Ecky

They're not grippy enough to hold the road in 1st gear and have had their life cut significantly short because of that.

This is NOT a problem one would ever have in a Mirage.



Interestingly, just before I sold the $800 Fit, I broke the inside tire loose on an uphill left turn from a stop. It was unintended... but I let it spin merrily away until the 1-2 shift just for fun.

Also neat that you're running the same 185 F 165 R tire width combo as I am on the Mirage. (Which I'm doing solely for the gearing change).

[Ecky]

There's also a lot more tire selection in that size!

14's in general are becoming scarce.

[redpoint5]

Why did wheel sizes increase? If larger is better, why didn't manufacturers simply start from a larger wheel?

[serialk11r]

Originally Posted by redpoint5

Why did wheel sizes increase? If larger is better, why didn't manufacturers simply start from a larger wheel?

Hmmm...bigger wheels have less centripetal force on the tire since they rotate slower at a given speed, so the tire can be made weaker in tension. I suppose the tread flexes a bit less reducing energy consumption and improves grip a little. Finally, I think customers think big wheels look cool, because wheels have been getting bigger and bigger while the tire sidewalls have been getting smaller and smaller.

I'm guessing it didn't start that way because they didn't want to spend money making big wheels when a small wheel would do. Unfortunately, tires for small diameter wheels are getting harder and harder to find, so we'll all be switching to big wheels at some point :/

[COcyclist]

Originally Posted by redpoint5

Why did wheel sizes increase? If larger is better, why didn't manufacturers simply start from a larger wheel?

More of the population lived where the roads were poor? It is really easy to ruin a low profile tire/rim on bad roads.

Suspension has gotten better? A tire with less sidewall depth generally rides harsher. There was a time when Americans wanted comfort over performance.

The real reason probably has to do with aesthetics. People want big rims with low profile rubber and huge disk brakes to look like a race car.

[Ecky]

Hopefully the tires get here soon. I'm starting to lose pieces due to... erm, hypermiling.

[Ecky]

Installed the new (front two) Vredestein Spotracs today, in the same 185/60r14 as the old Vredestein Quatracs. I inflated them to 44psi for breaking in, whereas the old ones had been inflated to 48. Max sidewall is 51psi.

I drove to the tire shop with two of my winter wheels on the front. It's a highway trip I make very frequently (to roughly the same area) and compared with the bald Quatracs, the winter tires seemed to deliver 3-4% lower fuel economy, in both directions, despite being 1.3% smaller (assuming full tread depth on both tires), or more likely nearly identical in size due to the summer tires being worn. With those winter tires I had not seen a significant decrease in fuel economy over RE92s, though I had never had a perfectly back-to-back comparison.


Initial impressions:


I made a similar trip today with the new tires, and got nearly the exact same fuel economy (52.5mpg, without P&G or EoC) as I would have with the worn Quatracs. The new tires may have a larger rolling diameter due to not being worn. I can't say for certain they're identical in revs per mile to the Quatracs, but my math shows a 1.3% difference in circumference between a completely bald and a brand new tire.

In other words, early data is very promising for fuel economy. I may put in another 7psi in a week or two.

They're a lot less squishy than the Quatracs, and very much quieter too. Both Sportrac and Quatrac tires are quite light for their size (14lbs), likely due in part to having very soft and thin sidewalls. Handling is very sharp. Early traction testing () did not show an improvement, but 1) the old tires had basically become slicks, and 2) the new tires have less than 25 miles on them.

Overall, I have a very positive first impression. And, at $86 each, I find it pretty hard to complain.

[Ecky]

Haven't updated in a while! Here's what's new:

My last few tanks have been the worst ever. I'm now living in metro Detroit, and the Insight was used very heavily as a pickup truck in the months leading up to the move, during the move, and after the move. I have a work vehicle I commute with now, so the Insight's job has largely been pulling a loaded trailer in Michigan city traffic.

This weekend I had a chance to diagnose and fix a few issues I'd been living with, which were all affecting economy. To name a few:

-I was having ready hard cold starts, worse the colder it got. Long cranking, and lots sputtering and dying until the coolant temperature was above ~120F. The issue turned out to be my gauge cluster converter. It's Arduino-based and the inputs used were programmed to be "pull-down", which puts a high ohm resistor in line. Unfortunately during cranking the Arduino would power down, then the inputs would not have any inline resistance, and they would pull down the voltage on the sensors they were reading - particularly the ECT. This caused the ECU to read a very high ECT whenever I tried to start the car, messing up the fuel and ignition compensation that is needed for starts on a cold day. I finally figured this out Saturday and, after adding a physical 50k resistor in line, the car started on the first crank on a 35F morning.

-For the last couple of months I had my lean burn tune disabled while I tried to troubleshoot this.

-Cruise control wasn't working, which turned out to be a wiring issue, from my being in a hurry.

-My kill switch wasn't working either. This ended up being a break in a solder joint to the ground. The kill switch is wired as a nitrous input, where the ECU adds negative fuel until the engine dies, and it simply wasn't seeing the switch close.

I also had some brake light wiring issues (turned out to be on the trailer's harness).

Next up is getting my A/C working again. I didn't give proper clearance for one of the lines and it rubbed on something until the system depressurized.

[NoD~]

All that right there is why I can't bring myself to do the swap... lol. I'd go insane! Bravo on finding the issues and fixing them. I figure, I'll just wait until you got it like 99.9% of the way there and get tired of it, then sell it. Then I buy it, fix the 00.1% and I got a sweet new Insight.