My Intake Test, Fourth (and final) Phase

[magnuman]

These intake tests have taken several months to complete, but here are my results from this last phase (Phase 4), as well as my opinions (for what they're worth), and observations. I'll summarize by including results from each phase so you can see, in a nut shell, how the various configurations worked. Also, the highway driving for this phase was two long trips of about 1500 miles each. To see how and why I did these tests, You can refer to the previous phases of this exercise at:
My Intake Test, Phase One Complete
My Intake Test, Phase 2 & 3 Complete

Notes: Inbound highway for Phases 3-4 there were moderate head/cross winds.
Also, Phases Three and Four the ambient temperatures had risen sometimes to as high as 105 degrees, with very low (15-25%) humidity. The highway tests for Phase Four were in altitudes from 290-7000 ft. elevation.

Phase One-Stock everything
In Town, 15.3 and 16.1 for an average of 15.7 mpg
Highway, outbound, 26.7, inbound 28.5 for an average of 27.6 mpg
Phase Two-K and N drop in filter
In Town,17.1 and 16.8 for average of 16.95 mpg.
Highway, outbound 27.1, inbound 25.7 for an average of 25.7 mpg
Phase Three-K and N drop in filter and additional duct from grill to airbox.
In Town, 17.7 and 18.1 for an average of 17.9 mpg
Highway, outbound 29.1, inbound, 25.4 for an average of 27.25
Phase Four-K and N, additional duct, and double wall, triple insulated intake.
In Town, 15.9 and 16.4 for an average of 16.15 mpg.
Highway, first trip 1521 miles, 25.22 mpg overall. Best tank was 446 miles on 16 gallons, for average of 27.87 mpg. Best leg was 178 miles, 30.3 mpg.
Highway, second trip 1446 miles, 24.55 mpg overall. Best tank was 438 miles on 16.1 gallons for and average of 27.08 mpg. Best leg was 132 miles, 27.5 mpg.

Comments/Observations: Installing the K and N and the additional 3 inch duct seems to be the best and easiest mods. to do. The insulated duct in Phase 4 only cools the intake air slightly more than the stock system on the highway. In town the insulated duct runs cooler inlet air and recovers quicker, but as you can see did not render the best mileage. Ambient temperatures 95-100, with 15-25% humidity may have been a factor. I will also say that on the best tank (446 miles/16.0 gallons) and best leg of the first trip (30.3 mpg) were obtained using regular (87) fuel with 7 oz. of acetone added to the fuel. Best mileage was obtained at about 4500 ft. elevation.
--If I were doing this over, and drove mostly on the highway, I'd do the first two mods. only. (K and N and additional inlet to airbox)
--If most of my driving was in town, I'd do them all again.
--Weather conditions and speeds driven have more to do with gas mileage than any of these mods.
--Acetone does do some good on the highway with my vehicle. City???
--Bottom line, as proven before....the stock system isn't too bad at all, but with the high prices of fuel these days, every little bit helps, IMO.

[CoolVanilla]

--Bottom line, as proven before....the stock system isn't too bad at all, but with the high prices of fuel these days, every little bit helps, IMO.

Great work MM. Thanks for the efforts!

[Falcon2358]

I will also say that on the best tank (446 miles/16.0 gallons) and best leg of the first trip (30.3 mpg) were obtained using regular (87) fuel with 7 oz. of acetone added to the fuel.

Goodday,

I was wondering how often you use acetone in your tank? Opinions on this are all over the map and range from the best thing since sliced bread all the way to melt down your fuel system. Have you used it in other cars before the Magnum? I doubt that there is much rubber hose in the fuel system but there are gaskets and such that seem to be suseptable to acetone degradation. Just curious to get a real world opinion and since you mentioned it I was wondering about your experience with this additive.

Ciao,
Falcon

[MAGNUM8R]

Very nicely done! I will wait before adding Acetone in the fuel filler though, even with the fact that I have actually washed my eyes out with very clean Acetone after having polester resin splashed in them. The stuff evaporates quickly when exposed to the environment and burns for short bit. The effects in a closed system are not proven enough to me to even thin k about putting it my tank.
Keep up the detailed reporting, this was realy cool!

[magnuman]

Falcon2358 and MAGNUM8R,
I've tried acetone in town in the RT and it doesn't seem to make much difference, but on the highway it seems to make a difference. I've used it maybe 6-8 times, and have no ill effects. My other high (mpg in the car, not me) with acetone was 29.8 last winter. Strangely, this last trip when I got 30.3 mpg at 4500 elev. also gave me only 25.3 mpg (same tank of gas) near sea level (290 ft.).
I've also tried, and continue to use, acetone in my "beater" Jeep around town. It definitely helps the mileage, idle and starting of that slug. Also MAGNUM8R, you're right about the evaporation factor. I let the Jeep sit for about two weeks and all the fuel evaporated out of the float bowls. Took awhile to start that time. MAGNUM8R, like you, I am still using the airtabs on the RT, and they definitely make a difference on the highway with crosswinds, passing trucks/campers, and keeping the window a little cleaner. They don't do squat in town. I haven't seen any improvement in mileage though. Also neat to have people wonder what they are?? Just did the spark plug wire mod. and am going to see if there is any difference in mileage with it. I figure it can't hurt now that both plugs on each cylinder fire together, instead of just one. Thanks for the cudos, and inquiry.

[Spali32]

Just curious on what the spark plug mod is??

[magnuman]

Spali32,
You can see the loooooonnnnng thread on the spark plug wire mod. at:
Quick, Cheap, Ignition Modification
A picture of mine is on Pg. 21, Post 206. There are also a few pictures of other members mods., too. Bottom line, IMO, it looks much cleaner, but I haven't seen any difference in idle quality, performance, or mileage. Plus, it'll be a lot cheaper to replace the wires when the time comes. Also, you won't need this mod. on your new Charger....it is already set up this way, but the coils cover both plugs, so there are no wires involved at all.

[Todd RT]

Magnumman, how are you getting that high of highway mileage. I'm lucky to see 22mpg here in FL if I go close to 72. If put the cruise on 79, I'll be lucky to get 21mpg. _05 Magnum R/T, 89octane.) ????????????

[magnuman]

Todd RT,
I think you just said it....cruising speed. I read somewhere that you lose more than 5% mileage for every 5 mph increase in speed above 60 mph. If true, you'd be dropping about 20% cruising at 80 mph vs. 60 mph. Most of my highway driving is 60-70 mph. Where I live it is 2800 ft. with rolling hills and slightly mountainous. I run nothing but 87 octane, and the best mileages were all gotten with about 6 oz. of acetone added to the tank. Normal is usually around 28 though. Even when new, my RT never got below about 24 mpg. My mods. are all minor, and most homemade. I run 40 PSI in the front tires, and 36 PSI in the rears. My alignment was done with me in the car, so it is properly aligned while driving. I run Mobil 1 oil with Mobil 1 filter. I built a double wall triple insulated CAI with an additional 3 in. ram air duct from the grill to the airbox, and a K and N drop in filter. I also have my MDS "on" indicator light,
Installation of a MDS ON Indicator Light
the spark plug wire mod. and Airtab vortex generators. I don't think any one mod. makes a big difference, but collectively, along with slower driving, they obviously make some difference.