Driving (MPG minded)

[MPGmustang]

LOL!!! :rolflmao:

Dang it the dyno ppl lied to me!!! lol jk

the speedo pretty acurate, I get to check every morning as I pass the "this is your speed _ _" sign. 45=45, 50=50, 55 = 55... I won't go any higher but it's acurate higher too... :roll:

yes, 1600 = 46.05
so mabye my eyeball wasn't dead on, on either the rpm or speedo... who knows... but rough ball park is all i can offer... lol

i'm just asking the question which gives more economy?
A) 4th at 2200rpm with 14hg or...
B) 5th at 1600 rpm with 11hg?

i've done trial and error but got the same or worse... maybe it's the starts the kill me mpg. need an egg (where did i put that rubber chicken?)

I'm starting a poll at the top...

 

[JackFish]

i'm just asking the question which gives more economy?
A) 4th at 2200rpm with 14hg or...
B) 5th at 1600 rpm with 11hg?

Well since you're the one set up to check it out we should be asking you that question!
Let us know how it works out, because I've been wondering about that myself, although I have a C4.
Is it more economical to drive around town in 2nd with a higher vacuum and rpm, or 3rd, because of the lower rpm?
I'm guessing that the lower rpms and use of the higher gear is cheaper.

 

[69.5Mav]

i'm just asking the question which gives more economy?
A) 4th at 2200rpm with 14hg or...
B) 5th at 1600 rpm with 11hg?

My max vac is 16, 15 most of the time

the engine is not stock, the cam is 264/274 with 110* lobe centers. so I don't get stock vac numbers

I would say you would get your best milage at A with your most likely stock vacuum advance unit.

With your cam and driving at the Altitudes (1200 feet) you do your vacuun will be low. You lose about 1 inch for every 1000 feet up.

From the sticky on ported vs manifold advance I gleaned the following.


Vacuum advance calibrations are different between stock engines and modified engines, especially if you have a lot of cam and have relatively low manifold vacuum at idle. Most stock vacuum advance cans aren’t fully-deployed until they see about 15” Hg. Manifold vacuum, so those cans don’t work very well on a modified engine; with less than 15” Hg. at a rough idle, the stock can will “dither” in and out in response to the rapidly-changing manifold vacuum, constantly varying the amount of vacuum advance, which creates an unstable idle. Modified engines with more cam that generate less than 15” Hg. of vacuum at idle need a vacuum advance can that’s fully-deployed at least 1”, preferably 2” of vacuum less than idle vacuum level so idle advance is solid and stable; the Echlin #VC-1810 advance can (about $10 at NAPA) provides the same amount of advance as the stock can (15 degrees), but is fully-deployed at only 8” of vacuum, so there is no variation in idle timing even with a stout cam.


On my 170 I run 12 to 13 at 55 cruz so I think I need the vacuum advance suggested and you might try it as well, it's only 10 bucks.

 

[JackFish]

Yeah, that's it, I have dithering idle.
But I run ported vacuum, so there should be no vacuum seen at the vacuum can at idle.

But this thread is about driving mpg, and you don't go anywhere sitting at idle.

 

[69.5Mav]

But this thread is about driving mpg, and you don't go anywhere sitting at idle.

"B) 5th at 1600 rpm with 11hg?

Most stock vacuum advance cans aren’t fully-deployed until they see about 15” Hg.

While cruzing in 5th at 1600 rpm you've only got 11hg so youre vacuum advance is not fully activated. This will decrease you mpg. So you might want to get this "the Echlin #VC-1810 advance can (about $10 at NAPA) provides the same amount of advance as the stock can (15 degrees), but is fully-deployed at only 8” of vacuum" to get your full vacuum advance while cruzing.

 

[MPGmustang]

intresting, I did read that thread and it didn't cross my mind... i'll call up DUI ppl and see what they recomend... should've done it sooner but live and learn...

Well since you're the one set up to check it out we should be asking you that question!
Let us know how it works out, because I've been wondering about that myself, although I have a C4.

Jack i've tried, on my 2nd tank now in 5th gear, and still got 16.2mpg... maybe this next tank will be better... tempted to just keep in 4th...

 

[MPGmustang]

Just got off the phone with PerfomDist... with my mod's (more cam and higher lift) they said the curve is just right (24* @ 3k rpm) and 12* initial advance would be perfect for the timing (i have it at 11*)

I'll swing by napa today and pick up a new can, should be easy to switch out, then i'll have full vacuum adv @ 8hg on up, which should help mpg and feather footing.

besides the feather footing, coasting to red lights, timing/making green lights, and just not using the brake as much, is there anything else I can do to improve mpg a little?

tire pressure = 36psi
I have tires 205/70r14 just checked, = 25.3 dia = 79.48 cir = 797.18 rev/mile = 47.64mph@1600rpm

 

[MPGmustang]

okay, I'm being skeptical but just throwing it out there... do we know if that part number works with the DUI?

I went to napa and got some of the following details...
VC-1810 starts vac @ 3.5-5 hg - DISCONTINUED (hence "fully deployed" @ 8hg)
VC-1807 starts vac @ 5-7 hg - next lowest

not knowing if these work properly with my application I called up PerfDist again, they said, "any HEI VC will work with the DUI" I'm very leary to think that it's a 'one size fits all'

I did find out that the only VC they give with their DUI is fully advance @ 14hg and they don't have a different one.

what do u guy's think?

But this thread is about driving mpg, and you don't go anywhere sitting at idle.

True this is "Vacuum Gage Driving" but if it's not working to best advantage while driving I'm up for little tweaks here and there to help economy. IMO more burn from vac = more hp with less gas (assumption there) @ coasting/maintaing speed

 

[cruzingratiot]

i drive my car never accelerate below 10 in of vac and drive at higest vac guage reading
for the best milage

pic of old motor minder guage like the one i use
http://www.smartcarofamerica.com/galler ... ageid=9415

 

[bubba22349]

:rolflmao: Good one Did you find your rubber chicken yet?

 

[MPGmustang]

Thanks Cruzingratiot! that helps!

The one on the right is the stock VC

went to napa last week and took a pic of the unit that they had. it was different than the one I had wheni quickly took mine off and checked thiers for same mount.
the pic is of a AC-1807 (same mount as the VS-1810) but as you can see the schrew holes are different.

I'mm still hunting and looking for what I can use at the 3.5-5 vac starts like the VC-1810 for a full advance at 8hg

this current tank I'm running no less than 10hg to accel except freeway ramps. so right now I just have to get used to going slower than traffic :|

I have done more research about my 65 mustang on the side of hp needed @ speeds @ RPM in each gear
the HP needed colum is an estimate IF the following conditions are meet:
flat ground
72* weather
No Wind

I didn't want to figure it out random wind senarios, i'm thinking about adding a grade % in the furutre but not atm.
My current HP @ 112 is a rough gestimate, i'll replace when i find the real HP.

 

[falcon1963]

All depends how wild the cam is.

Mild cam it will pull at lower rpms, wild cam it needs higher rpms.

There are 3 pedal positions in my book. Idle cruise & WOT.

I could care less about mpg.

Engine settings optimum thats all i care about.

You get what you got.

 

[MPGmustang]

okay got to lopers and asked for a generitc HEI adjustible VC, what do ya know they had one. it fits too.

there is a difference the second I start the car, the "dithering" as it was refered to has mellowed out alot, I put the spirng softer than the stock can but not at it's easiet setting as I don't want ping yet cause I didn't have time to fine tune it.

Till next tank

(PS last tank was 17.5 )

 

[MPGmustang]

Well, already disapointing...

I traveled 255.4 miles used 14.548 gallons, I received 17.55 mpg took me 6 days, and traveled avg of 43miles per day.

I strickely stayed in the 10+ hg range. drove like a "older guy" and was cut off many times by drivers. even drove the exact speed limit or slightly slower.

is it my driving habits?

carb = v1100
jet = 64 (came stock with 59)

rest is in sig.

 

[MPGmustang]

I traveled 253.1 miles used 14.559 gallons, I received 17.38 mpg took me 4 days, and traveled avg of 63miles per day

THIS time I drove with a heavy foot, not the heaviest... absolutly no highway speeds but I accelerated @ mostly 5 vacuum and then stayed in 5th @ 10hg to maintain 49-50mph

this is the 3rd recording of 17mpg in a row. EACH with different driving. I don't think it's driving habit now I think it's something else... what do you guys think?

 

[69.5Mav]

MPGmustang

Try having your alignment checked both front and rear.

Also check every rubber hose that gas flows through and the gas tank for leaks.

If those don't help them get an ox sensor and check the mixture.

After that I am at a lose.

Good luck

 

[MPGmustang]

Try having your alignment checked both front and rear.

Can't afford it but I do know the tires wear evenly on the tread (checked reguarly @ 35psi)

Also check every rubber hose that gas flows through and the gas tank for leaks.

no leaks, I changed my gas filter Just in case, air filter too as it was time

If those don't help them get an ox sensor and check the mixture.

you know of a cheap setup? (less than $100)

Well went on my MPG drive again... this time I used 89 octain (no ping!!!)
Chandler to Flaggstaff = 17.1 mpg
Flaggstaff to Chandler = 23.5 mpg
avg = 20.3

 

[ludwig]

Sounds about right at this point.

 

[MPGmustang]

If those don't help them get an ox sensor and check the mixture.

you know of a cheap setup? (less than $100)

I've called around and all of the kits are +300 I'd rather re-wire my car with a painless kit...

10-28-10
I traveled 247.2 miles used 14.321 gallons, I received 17.26 mpg took me 5 days, and traveled avg of 49 miles per day
Tried to keep decent vacuum but drove my way, get up to speed and maintain high vacuum, usually 4th gear sometimes 5th, right before I filled up to take this reading I swapped from 64 jet to 62 jet

11-1-10
I traveled 243.5 miles used 12.518 gallons, I received 19.45 mpg took me 4 days, and traveled avg of 61 miles per day
Same driving as above, but this driving was with a 62 jet, I noticed I lost some rpm, no doubt it's from the smaller jet, I'll do one more tank/read before I swap to a 61 jet.

Oh yeah, i'm now on 89 octane gas, no problems.

 

[ludwig]

Are you going up and down, changing elevations drastically, like 3 or 4 thousand feet? That will affect the milage if you using low altitude jets and higher altitudes and vice versa. The other thing is that you could have a different counter giving you bum data, like the odo skipping or whatever. The milage will improve straight away if you have electronic ignition. And watch the show of speed at stops, corners and lane changes. I know you are hip to the skip on all this. I just had to say it. I'm thinking you are getting driver differences by now. I get about 20-21 mpg on the highway and 12-14 in town on 89 octane and you are in that neighborhood.

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