Makeing an efficent freeway flyer.

[H-Man]

8/31/15 EDIT:
Already broke 50% of EPA combined. Turns out that an old cat had left behind a chunk of substrate in the pipe so I had about the exhaust flow of a lawn mower. Pulses are now beneficial and I can hit numbers on open road that I used to need to be drafting a semi to achieve. A crack in my exhaust manifold was leaking, replaced. Now I can go chase other gains. My TDCL cable works now so I can actually record what sensors are doing to a limited degree and figure out how to keep the engine out of enrichment more.
Challenges: My commute has me driving in still air in the morning but the wind picks up by noon and I'm driving into a 10MPH headwind in the evening, the last leg of my morning commute and first leg of my evening commute has me in a parking structure that has aggressive speedbumps.


7/10/15 EDIT: *Ataches electrodes to thread*
*Puts up lightning rod*
*Realizes that I'm in socal so waiting for lightning will take a while*
Screw it. 3... 2... 1... CLEAR!
*Necros thread*
Change of objective: I'm an engineering major now and being able to say as a project I applied, tested, and evaluated modifications with an ultimate result of a 50% increase in fuel economy over my baseline fuel economy should look at least somewhat interesting to employers looking for an intern.
I'm getting around to installing the MPGunio.
Currently done:
Base timing is increased from 10 degrees BTDC to ~13 degrees BTDC, the max timing that will pass the inspection component of a california smog test.
WAI (only used when temperatures are low enough to allow).
Upper Grill block (only used when temperatures are low enough to allow).
Air dam.
Better tires (Michelin Defenders, 185/70/R14)
NGK spark plugs (seems that the 4A-FE loves ngk and denso spark plugs)
10W-30 Mobil1 Extended performance synthetic oil.
AMSOIL MTG 75W-90 GL4 synthetic oil in gearbox.
Phillips Xtreme Vision low beams (smaller and hotter filimant means that they put more light out the front and don't dim to the point of uselessness when in EOC).
LED interior light. Old draw was 1 amp, new draw is .1 amp (I used 2 LED sign backlight modules at .05 amp each, I could use 1 if my dome light's plastic wasn't opaque from age).
In the works: Rear wheel skirts
Smooth hubcaps if I can find suitable material
New front motor and front exhaust mounts to make drive more doable.
TO TEST: Determine conditions ECU goes into enrichment and have an indicator for when it goes into that.
Determine cooling requirements for car on highway.
Determine fuel cutoff behavior.
Calculate current cd and frontal Area.

END EDIT

I want to try to keep my car efficient even when doing 70mph-75mph (or according to my speedometer: 65-69 MPH) on the freeways. Since most of the energy will be expended to move through the air, I'm going after aerodynamic losses first.
I'm thinking an air dam and side skirts as a starting point, maybe something on the front wheel well.
Target MPG at 70 MPH is 40 MPG.
I am contemplating figuring out a way to have an swamp cooler setup so that I can cool the cabin when the air is 100F outside (at 20% humidity,) without compromising FE.

[wmjinman]

Clearly, the biggest impact on freeway MPG is speed. So the easiest way to improve is by slowing down.

However, if that option is "off the table", then the aero improvements will be "it". Work on the grille block; the more complete, the better, but watch your engine temp. I think a full belly pan might be more effective than air dam & side skirts. Others have made great improvements by kamm backs and boattails.

Rear fender skirts seem to work better on some cars than others. Unless someone else here has firsthand knowledge about your particular model, you might want to experiment.

Cutting the drag from your outside mirrors can help too, either by eliminating the mirror(s) you can, or replacing them with much smaller ones.

Putting even more air in your tires could help a bit, too...

[H-Man]

Originally Posted by wmjinman

Clearly, the biggest impact on freeway MPG is speed. So the easiest way to improve is by slowing down.

However, if that option is "off the table", then the aero improvements will be "it". Work on the grille block; the more complete, the better, but watch your engine temp. I think a full belly pan might be more effective than air dam & side skirts. Others have made great improvements by kamm backs and boattails.

Rear fender skirts seem to work better on some cars than others. Unless someone else here has firsthand knowledge about your particular model, you might want to experiment.

Cutting the drag from your outside mirrors can help too, either by eliminating the mirror(s) you can, or replacing them with much smaller ones.

Putting even more air in your tires could help a bit, too...

Slowing down seems too easy to me. It seems far more fun to make the car get crazy good FE at FSP speeds (I like a good challenge.)

[wmjinman]

I completely understand!! Do the "crazy" just to see if you can do it!!

So, if you don't yet have a ScanGauge - (oh wait, I just saw you have a pre-'96 car & plan to get the MPGuino) - get it soon. Testing your mods one at a time is MUCH easier, faster, and cheaper with one of those devices than trying to do it "fill-up to fill-up".

Read MetroMPG's "correct way to do A-B-A testing" thread and use that technique to figure out what's happening with everything you try. The good thing about wanting to do higher speeds is the aerodynamic differences will show up better that way. Aero mods won't be as pronounced at 50 as they will at 70.

I'm anxious to see how you make out.

[razor02097]

I think it would be helpful to know what fuel economy numbers you get now at 70-75mph. Improvement can only be measured if you have a baseline to compare.

[YeahPete]

For the air conditioning thing. I used a spray bottle and sprayed myself. It worked quite well! I did leave the interior fan on with my window cracked.

[H-Man]

Originally Posted by razor02097

I think it would be helpful to know what fuel economy numbers you get now at 70-75mph. Improvement can only be measured if you have a baseline to compare.

Looking at my logs. I think I get 36 at 70 (and 30 at 75 if I hit stop and go traffic and city traffic ) if the pump is correct, but I don't trust the pump so MPGunio it is.

[justme1969]

read my 2nd car kia success blog never made the 40s but hit 36 two times just not sucessively and in the end im happy now that my avg norm of 31.5 at 75 is done deal.
I go over alot of stuff so it could sound like rambling perhaps but all tried and true and tested. Ive just never been happy with the refill procedure. I go so far as same route repeated for 2 round trips exactly, and same fuel pump at same time of day but dont have hard evidence to back up full tank theory.

oh and I went with a try it and be a skeptic approach. I still swear a spoiler and a air dam behind it is the way to go.

[brucepick]

I'm sorry to say I think you will need to get past your distrust of pump gallons data. That's because you will need to calibrate your MPGuino after hooking it up. And guess where you get your actual gallons data? Yup, the pump display.

Read some of the threads on fill technique. Briefly: consistency is the key. Same station, same pump. I try for same time of day (roughly) because gasoline expands considerably with temperature increase. Same squeeze pressure.

As for myself, I squeeze about 3/4 until about a gallon short of full. Then I relax to a pretty standardized very slow rate till it clicks once. Check my Civic's gas log over recent months and you'll see notes of actual fill vs MPGuino estimate. Very close.

And BEST OF LUCK wig the highway mpg quest. I've been on a similar path for some years, with a current commute of 55 mi each way.

[Cobb]

Yes, aero is the way to go. If you go twice as fast you are going to encounter 4 times the air resistance.

I routinely drive those speeds in my insight and still net 40+ mpg without my phev kit.

And this time of year I use a full upper and lower grill block.