Driving (MPG minded)

[MPGmustang]

Are you going up and down, changing elevations drastically, like 3 or 4 thousand feet?

Nope, all driving unless stated is all in town here in chandler/mesa/gilbert, all 2000ft elevation no more than 50ft difference over 4-5 miles
it's even more weird tho, going from 2000ft chandler to 7000ft flagstaff and @ 65mph+ i still got 17mpg UPHILL!!!

I get about 20-21 mpg on the highway and 12-14 in town on 89 octane and you are in that neighborhood

I used to get that with my old carb holley-1942, the pony carb became 18 insta and the tranny gave 20-21 insta...

The milage will improve straight away if you have electronic ignition

That's what i've heard, but i've seen worse mpg insta with this DUI setup, I have a new adj vac can and still no difference, :x very disapointed in mpg, but performance increased

The other thing is that you could have a different counter giving you bum data, like the odo skipping or whatever

Very true, the needle @ 10-30 the speedo jumps all over the place but it's dead on at 35+ this is going to be resolved, it makes sence. what do I need to replace? the cable or speedo, and where do I get a speedo odo?

I'm thinking you are getting driver differences by now

hmm... but if i've gotten 17mpg every time? even behind traffic or with traffic or ahead of traffic? that doesn't sound right

My wife could probably get more miles out of a tank but I like the exhaust rumble and the pressure in the seat.

If i had a wife this would be her daily, while i work on the next one... but i completely agree with the rumble and pressure

 

[ludwig]

Just try the Pertonix I. It's $80. Just try it. Takes 1/2 hour to do. No mods. Put the points back in if you don't like it.

 

[MPGmustang]

Just try the Pertonix I. It's $80. Just try it. Takes 1/2 hour to do. No mods. Put the points back in if you don't like it.

My previous ignition was a LOM with pertonix I and 40k coil... now i have the DUI, and starting it is lil harder when cold

 

[MPGmustang]

okay, reviving the thread... so again I saw someone getting 28mpg... on a relativly stock motor

I know performance with some mods help but I'm just not getting it obviously

MPG I would like a city driver to get 21+ mpg, I'm finally stable @ 18 mpg city (and currently I'm not even running A/C)

current setup

78 head - ported and valve guides
stock rockers
1.75int 1.5exh
CI header with true dual 2 inch pipes with 14inch magnaflow's
cam - 264/274 110* .450 (advanced 4* with CI dual timing chain)
DUI - manifold vac (i'm timing it off vacum, atm don't know timing)
autolite 1100v with 65 jet (59 stock jetting, can run 62 but seems too lean atm)
89 4cyl t-5 tranny
3.27 rear end
205/70-14 tires (25.3 dia)

cam rpm range is 1600-5200
my driving rpm range - how low can I go... I'll go 45mph in 5th and 1500rpm without bogging/detinition
have a vacuum gage on steering column and I'm staying between 5-16 vac, mostly 14 while maintaining speed
idle is 900rpm, 13 vac, ? timing, and it don't ping at higher speeds uphill

What else can I do, of "IF" I went to replace something to increase my city mpg to 21+, my driving habits is what's keeping it @ 18mpg atm...

go radical... I'm thinking a super charger with 5 max psi...
next steps, remove mech fan and go electric with 1 wire alt, new stock wire harness... heard this could push me 2mpg more
change cam?
add what?

I know it depends on the driver, but i'm driving city so would like somehting better than 20

Edit: oh yeah, I sill get to replace the speedo gage

 

[170-3tree]

When you drive around town, do you tend to try for the lowest rpm? The best thing I've done in any vehicle is figure out the power curve and drive a bit below the peak most of the time. It helps a lot. (not the same vehicle, but similar theory) If I take my mazda (6sp) out and try to get the highest MPG's in it I can cruise through town in fifth gear smoothly going about 30-35, and receive about 27 mpg with a somewhat hilly road, but drop into fourth go from 1200 rpm to 2000 rpm and get about 33mpg on that same road that same day. I can't compare my Six because i cannot track the numbers nearly as close, but when they say drive with a vac. gauge they mean to try to keep the vacuum up on accel. you want your car in the operating range as much as possible. That way you don't have to downshift up hills or bog the engine down.

BTW I drive like a bat out of heck with my car in my sig, I get about 23-26 mixed, not that that amounts to much against your bigger and slightly beefed stang.

 

[jet471]

okay, reviving the thread... so again I saw someone getting 28mpg... on a relativly stock motor

I know performance with some mods help but I'm just not getting it obviously

MPG I would like a city driver to get 21+ mpg, I'm finally stable @ 18 mpg city (and currently I'm not even running A/C)

current setup

78 head - ported and valve guides
stock rockers
1.75int 1.5exh
CI header with true dual 2 inch pipes with 14inch magnaflow's
cam - 264/274 110* .450 (advanced 4* with CI dual timing chain)
DUI - manifold vac (i'm timing it off vacum, atm don't know timing)

My thoughts are that mid to high 20 mpg's with your setup will be unattainable. Don't get me wrong, I like your setup for power and fun, I just don't think it is great for mileage.
The reason behind this, I believe is the late model ported head with larger valves and a cam with more lift, this combination should automatically flow more fuel.
I assume when you rebuilt the motor you went for a decent compression ratio, I forgot if you stated that in your sig.

Feel free to correct me if I'm wrong.

Good luck with your quest.

Josh

 

[MPGmustang]

thanks guys, I do see the error in MPG minded build, I didn't want mpg, but still think that from my stock engine to my modded engine it should've been better right? (sime size car/engine, but more HP should = more MPG)

well, I recently took the v8 mech fan, with 6 fixed blades, off, and installed an electric fan, my road mpg avg went from 21.5 to 24.6mpg, I even hit 29mpg on a down hil leg that I used to get 25mpg, intown I'm still fiddling with the carb alittle as it's warming up now that summer is here.

for driving with the vac, I've noticed an increased "smoothness" to the car as I accelerate with as much vacuum as I can, currently I'm running 5th gear round town as much as possible with low RPM and High vac, I'll test 4th gear next tank. I think it might be the same as here in chandler there are no hills, but It would still be good to know if it increases.