Ecomodding an automatic '04 Civic Sedan

[Vman455]

Originally Posted by mpg_numbers_guy

Traction, what Xist said.

That all depends on the tire design, though. The OEM (LRR) Yokohama Avid S33's on my Prius were crap in the snow; the (LRR) Continental TrueContacts on there now are pretty decent in it. I checked the Tirerack surveys to make sure of that before buying.

[Ecky]

I'm aware of a guy on InsightCentral who runs 120 PSI in his Bridgestone Potenza RE92s. He gets phenomenal mileage, but also says he can lose as much as 30psi from the tire if he hits a pothole. I expect it's pretty nasty on his bushings and struts.

Not every tire is going to handle high PSI well, too. You may find that at 60, yours are very fragile, and you blow one out (completely ruining any economy you gain). Or maybe not. I personally run max sidewall in mine.

[mpg_numbers_guy]

Thanks for the tip, both of you. I think I'll try 50 PSI first, and increase by 5 PSI up to 60 if they handle fine.

I think I found my new perfect driving technique - only doable at night when there's no traffic:
1. Accelerate to 40. To 30 in 2nd gear, 3rd gear 30-40.
2. Foot at 30% load in OD down to 30 MPH (75-85 MPG)
3. Neutral at 29 MPH down to 17 MPH.
4. Reaccelerate to 40 MPH from 17 MPH. 17MPH-30MPH in 2nd gear and 30 MPH-40 MPH in 3rd gear.

Netted me 64.3 MPG on a trip where my best was under 61. You should be able to travel a mile to two miles per "cycle". Instead of keeping a constant load you're demanding higher MPG and maintaining it for as long as possible.

However I won't be able to use this technique unless there is absolutely zero traffic, which is only at night after 10 PM (and I usually get out of work at 10:15p-11:45p so this might work most days). Personal driving is ~56 MPG for this tank so far, but I've been driving faster during pizza deliveries and getting ~38 MPG, so my tank is again only a little over 40 MPG.

It's officially past midnight now, so I can now say that I'll have my new wheels/tires on tomorrow (the 2nd)!!

[Xist]

Blow outs can ruin all kinds of things, including your day.

[mpg_numbers_guy]

True, sigh. I guess I'll content myself with 50 PSI...but still!!!

With my new nighttime driving style I averaged over 60 MPG today...57.8, 63.3, 62.9, and finally 62.5 MPG indicated by Torque. Torque is generally between 2%-5% optimistic.

Tires & HX rims get mounted tomorrow!

I redid my lower grille block using black painted coroplast (Rustoleum seems to work well on plastic!!)....discovered there was an ants nest in my cardboard one! Will post pics tomorrow after I get pics with my new wheels!

[teoman]

Must have been one hell of a rollercoater ride for them.

[mpg_numbers_guy]

Originally Posted by teoman

Must have been one hell of a rollercoater ride for them.

I only do that at night when there's no traffic...duh!

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

Tires & HX rims being mounted now!

[mpg_numbers_guy]

Oh. My. Goodness. I LOVE these HX rims!

Had to put quarter-inch spacers in to clear the brake calipers, but tires are still further inset than my original ones.

BUT, they're working wonders on my MPG! I mounted new coroplast smooth wheel covers that look amazing compared to my previous ones. MPG has gone up by about 3.5 MPG @ 40 MPH. Wheel covers previously tested at +~1 MPG @ 40 MPH, so I can say with fair certainty that this wheel+tire swap has gained me 2.5 MPG @ 40 MPH in city driving.

The most noticeable benefit isn't the improved acceleration, but that I can keep a lower % load and still maintain the same speed.

Old wheels/tires:
- Stock 7th gen Civic Sedan 15" alloys (18lbs each)
- 195/60R15 all-season tires (16.5lbs each)
- Tire pressure @ 44 PSI.

New wheels/tires:
- 6th gen Civic 14" HX alloys (11.5lbs each)
- 185/70R14 all-season tires (16lbs each)
- Tire pressure @ 52 PSI.

Even driving home from the dealership with their default 35-36 PSI in the tires I could notice an improvement.

I'll try to get pics posted tomorrow! I work and then I have a long drive to New York over the night where I'm hoping to break over 50 MPG (my highway trip to Virginia was 49.1 MPG).

Going to try my 4th attempt at wheel skirts tomorrow, this time out of coroplast instead of cardboard, and they should hopefully work since my tires are narrower.

Also, tonight I made a new MPG record! Absolutely zero traffic permitted me to do extreme hypermiling the entire way! Accelerating to 40 MPH, foot lightly on the gas for 80 MPG instant readout down to 30 MPH, at 29 MPH shift into neutral until 19 MPH, then accelerate briskly to 40 MPH and repeat. Netted me 68.5 MPG indicated, which with the 2%-5% optimistic readout that Torque gives, is still between 65 & 67.2 MPG.

If only I could have perfect driving conditions all the time. On the way to work there was more traffic that required me to drive the speed limit half the time, and I still got around 58 MPG indicated (55.1-56.9 MPG actual).

I'm lovin' it.

[Ecky]

Just to be sure, you're taking into account the slightly different distance traveled because of tire size?

[19bonestock88]

Great work so far! Got any pics of new setup?