Ecomodding an automatic '04 Civic Sedan

[mpg_numbers_guy]

Weight reduction time! Nothing super serious, but hey, it all adds up:

- Front passenger seat
- AC blower fan
- Glove box
- All floor mats except driver's seat's
- All headrests except for driver's seat's
- Board and liner covering spare tire compartment in trunk
- Food crumbs and almost $1 in change under the seats from previous owners

Next to go tomorrow:
- Rear seat and cushion (if I can get the bolt out)

Also disconnected the trunk light to avoid unnecessary electrical use since my trunk is open most of the time while working on it.

Bought a 48" by 96" sheet of white coroplast today and made wheel covers for the HX rims when I get those on. Spray painted a test sample and it seemed to stick fine; I'll pick up some flat black paint for the wheel covers tomorrow and see how they turn out.

[Ecky]

Our cars probably look very similar right now on the inside!

[mpg_numbers_guy]

Originally Posted by Ecky

Our cars probably look very similar right now on the inside!

I don't think I'm as far along as you are. Not planning on gutting everything in the interior. Have to make it so that I can easily put stuff back in if/when I have to transport people. I did manage to get the rear seat out today.

------------------

Ok, I'm almost panicking here, someone reassure me or give me a wakeup call!

Acceleration is improved with the weight reduction, and it takes a lower load to maintain a cruising speed. Drove faster today and still averaged mid-upper 50s MPG during personal drives.

Downside is, my car is lifted by about a quarter of an inch. AND apparently my current tires are 195/60R15s, not 195/65R15s, so the tires I'm getting (185/75R14) are ~0.7 inches taller, which will raise my car up by another half inch or so.

I don't want to buy lowering springs for my car! Someone please explain to me how taller tires help fuel economy - I'm second guessing and considering returning the tires and spending $100 more to buy 175/75R14s!

Actual weight figures:

• Current:
  • 195/60R15
  • Height: 615mm
  • EX rim weight: 18lbs
  • Tire weight: 16.5lbs
  • Total weight: 34.5 lbs
• HX w/ 185/75/R14:
  • 195/60R15
  • Height: 633.1mm
  • HX rim weight: 11.5lbs
  • Tire weight: 16lbs
  • Total weight: 27.5 lbs
  • Cost: $151.08
• HX w/ 175/75/R14:
  • 195/60R15
  • Height: 618.1mm
  • HX rim weight: 11.5lbs
  • Tire weight: 16.5lbs
  • Total weight: 28 lbs
  • Cost: $243.72

Taller tires help highway economy, but I don't want them hurting city fuel economy! I don't want my car to be raised! Will it all be okay with the tires I ordered or should I go with my new gut feeling to return them and get the more expensive but more compatible 175/70R14s????

[Ecky]

Taller tires are the same as taller gearing. The only reason no to go bigger is that they usually weigh more.

All else being equal, a LRR tire will often deliver 5-15% better economy than a non-LRR tire, but it may not be cost effective if they're a lot more expensive.

[mpg_numbers_guy]

Originally Posted by Ecky

but it may not be cost effective if they're a lot more expensive.

^^That^^ I have to remind myself that part of ecomodding is saving money, not just MPG numbers. Went with a set of all season 185/70R14s (same size wheel as on Civic hybrid) on sale for $129. Tires come July 31 and my appointment for getting them mounted and balanced is Aug 2, the day before my trip to New York. The narrower tires I really wanted were about twice as expensive due to being a less-common size, and were a lower quality brand as well. All in all the wheel/tire swap will be costing me roughly $300, and if I can't make that or close to that selling my current rims/tires, well then I'm screwed lol.

Noticing roughly a 1 MPG drop without my wheel covers on, and more dust being kicked up on dirt roads (drag?).

Recap:

Tail extension was removed since it helps MPG and hurts MPG depending on conditions. Unable to determine a net gain/loss so I removed it.

Mirror boattails flapped too much at 45+ MPH so I removed them.

Wheel covers are off after my brakes heated up from my trip and will stay off until my new tires are on.

I'm down to just a grille block and air dam! And still easily beating 50 MPG! However trips that should be upper 50s MPG-wise are "only" mid-50s due to my lack of ecomods.

I need my new rims/tires mounted so I can mount my new wheel covers and do my 4th attempt at wheel skirts!!

[Ecky]

Some quick math on LRR tires:

4x Michelin Defender ~ $370
Mount and balance ~ $80
90,000 mile warranty (and my experience is that they do last this)
48mpg over 90,000 miles = $5,625 in fuel
Total cost for 90k miles of ownership: $6075

4x Hancook Optimo ~ $165
Mount and balance ~$80
70,000 mile warranty (multiple tire and mount price by 9/7) ~+$70
44mpg over 90,000 miles = $6,135
Total cost for 90k miles of ownership: $6,450

This assumes, of course, that the tires last as long (no more or less) than their warranty, and that you can get ~9% better economy out of the Defenders. The break even point in terms of fuel economy would actually be ~45mpg, so you'd be better off with the Defenders in the long run (but with more up-front cost) if you got even 1mpg improvement.

[Xist]

Originally Posted by Ecky

4x Hancook Optimo ~ $165
Mount and balance ~$80
70,000 mile warranty (multiple tire and mount price by 9/7) ~+$70
44mpg over 90,000 miles = $6,135
Total cost for 90k miles of ownership: $6,450

What about this guy:


He paid $300 for generic non-LRR tires with a 40,000-mile warranty, but not road hazard. He is selling the car, so maybe it is worth saving $15 for someone else's problem. Also, the car allegedly has a CEL for a bad gas cap, but he is not paying $8 for that.

At what point is it worth replacing non-LRR tires?

[Ecky]

Originally Posted by Xist

At what point is it worth replacing non-LRR tires?

The math almost always works out in favor of LRR tires, even if non-LRR tires are free. I would say though, that at the very least, when your old tires are worn out and you plan to keep the car for the duration the new tires last.

[mpg_numbers_guy]

I thought LRR tires were only good for 1, maybe 2 MPG, not 4 MPG? And what about the added cost of having to buy winter tires since one can't run LRRs in the winter?

[Grinder74]

Why can't you run LRR tires in the winter?