Who is BS'ing who?

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lets not forget about those cars were the speedo reads 5 mph fast. that is an easy area to pick up a few mpg, ha ha. How many cars have the right number tooth speedo gear--about as many that has all 4 tires at the right air pressure. It can be done but you have to do your homework. One number of teeth off and the speedo reads 2.5 miles different, two numbers its 5. Pretty good for selling the car--seems faster than it really is, look how fast the speedo climbs when you floor it, lol
 
In my stock 318 '72 dodge dart with a 4bbl eldelbrock intake, 600cfm holley, and headers/dual 2 1/2" exhaust with 2.76 gears I get 15-16mpg going 80mph. I get worse mileage at 60mph compared to 80mph. at 60 im barely turning 2,200rpms. At 80 im turning 2,900-3,000rpms.
 
i get 11 mpg highway on my 360, 11.2 to cr, single plane, holley 750 dp, 4,400rpm 9.5" stall, 3.55 gear. the hi CR helps with engine efficiency.
 
72DartCustom said:
In my stock 318 '72 dodge dart with a 4bbl eldelbrock intake, 600cfm holley, and headers/dual 2 1/2" exhaust with 2.76 gears I get 15-16mpg going 80mph. I get worse mileage at 60mph compared to 80mph. at 60 im barely turning 2,200rpms. At 80 im turning 2,900-3,000rpms.
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only a moron could think going 80 MPH will get better MPG than going 60 MPH
go back to school and learn something, your ignorance is astounding
 
caferacerx said:
only a moron could think going 80 MPH will get better MPG than going 60 MPH
go back to school and learn something, your ignorance is astounding
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The only moron is you for assuming you are the "expurt". When you obviously arnt. There is not a drop in fuel economy in my dart driving 60 compared to 80. If anything it gets the about the same, or very slightly better. My friend owns a 04 inline 6 Lexus is300 with instant fuel economy on a digital disply, and even he gets better MPG going FASTER compared to the speed limit. Not lead footing here.
 
caferacerx said:
only a moron could think going 80 MPH will get better MPG than going 60 MPH
go back to school and learn something, your ignorance is astounding
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And as 805moparkid said:
"the motor needs to run in its rpm range first... so with a big cam hyw gears are gonna kill you... you need to be cruzing at 3 grand or so going down the road...
ive heard different theories as to is you shoulds run when the cam "cleans out" or peak tq...
i think its somewhere in the middle lol"

At 80mph im at a 2,900-3,000rpm crusing speed and Its also where I get the most tq from my engine. The gas pedal isnt pushed down much at all to sustain that speed with 2.76 gears. There is a lot more to gas mileage than just how fast you are going.
 
72DartCustom said:
And as 805moparkid said:
"the motor needs to run in its rpm range first... so with a big cam hyw gears are gonna kill you... you need to be cruzing at 3 grand or so going down the road...
ive heard different theories as to is you shoulds run when the cam "cleans out" or peak tq...
i think its somewhere in the middle lol"

At 80mph im at a 2,900-3,000rpm crusing speed and Its also where I get the most tq from my engine. The gas pedal isnt pushed down much at all to sustain that speed with 2.76 gears. There is a lot more to gas mileage than just how fast you are going.
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well wind resistance has a big play in it to is what i think he was getting at...
 
805moparkid said:
well wind resistance has a big play in it to is what i think he was getting at...
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Well I dont know what to say. I drive a 30 mile round trip twice a week. And whether I drive 60 or 80 on the highway, $10 worth of gas puts my gas gauge at the same spot as it was before I took the trip. (gas has been $3.79-3.85 per gallon here) If there is a difference, it doesnt show on the gas guage.
 
For what it is worth one of my sport bikes got better fuel mileage at 75 than 55, at 55 in 6th gear the bike was a bit below where it was most efficient and in 5th it was revving higher than it was at 75 in 6th.
 
I beat the crap out of my bone stock '71 318 (original 2bbl) with a 650 DP, long tube headers, OD 4spd and 3:55 rear 235/60r14 and get 18.5 on the freeway (65-75mph) and 16.5ish combined. I am red lining it all the time and doing big smokeys whenever I feel like it.


I just swapped a set of 302 heads on and took care of the vacuum leak on the intake manifold and I am hoping to get 20mpg. I am gonna switch to a different carb though, another 4150 Holley but this one has 450cfm primaries with 800cfm secondaries bringing it to a 650cfm overall.

And yes driving faster with some combos will result it better millage, it's all about how the car is set up ect...
 
SirDan said:
First of all, to you people who say " if you worry about gas mileage get out of the hobby", are you denying financially less fortunate people to own a cool car? that just ain't right.

What about young guns in college? we shouldn't own cool cars?

and back on topic,
I don't get very good mileage with my 318 but, I have not done much to tune it. I think its possible with the right components and the right tune.
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It's simple economics. If you have a car, new or old, that sits in your driveway because you don't have the gas money to drive it, don't you think you need a life priority change? It's not about denying anyone anything. We live in a capitalistic market and everything is available to all.
I don't believe in having something I can't use.
Cars can get decent mileage if you put the effort into them, but this still may not help those that are considerably tighter with money in the real world.
My 6pk gets about aprox.10-12mpg, not the greatest, but I live with it.

ps- none of this is personal, jmo
 
Sixty five posts in this thread and we've heard about 318s, 340s, 360s, slantys, motorcycles, GMs and Lexus'. We've had all the experts chime in on how to get better gas mileage out of your ***. No one has chimed in on how they are getting such great gas mileage out of their strokers.

The original poster is calling out a couple of specific members who made pretty incredible claims on another thread. Now they are silent...
 
cuda67, I'll help you cut through the BS and get to the "factual" information. Here goes…

cuda67 said:
I really don't care, if I wanted mileage I would have gone to a 6 cyl.
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Agree. I did not build my 408 for mpg. But I did build it to be street driven, and driven distances (measured in hundreds of mile). The "rules" I set for my build were: great torque (torque is king on the street), good horsepower, and it had to look old school. For me old school meant that I was going to use an LD-340 (dual plane), mechanical fuel pump, stock appearing ignition (used FBO system) and my 1991 360 with 308 heads.

cuda67 said:
Wow, what stories are being told here about gas mileage. I have read with much interest the reported 12-18 mpg with 408 strokers and 360's, I say caca to this. …I just like to put out factual information to other folks that may be interested or curious as to MPG in a certain drive train and engine and not fantasy.
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Okay cool, you like factual information, me too. So why don’t we turn your rant into some facts so others who are looking to build their motor have a basis in fact.

cuda67 said:
I now have about 250 miles on the new Mopar crate 360/380 magnum with a 770 Holley street avenger, Mopar M1 intake, 904 tranny, 323 sure grip and 3000 stall and the mileage is 8mpg not 12 or 15 or 18 as some people claim.
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My proposal; I’ll outline my engine build and drivetrain specs, and you post your info right next to mine for comparison. Then we can let folks analyze the factual differences between our builds. I believe we both built fast street cars so this should be a good comparison.

For everyone else; If you compare your build to mine remember I did not build this car to be a “race only” car or motor. Yes, I know I could have gotten more horsepower/torque if I had only (you fill in blank). So go back and read my rules for my build. Let’s keep it in line with cuda67’s original premise that decent performance and livable mpg cannot co-exist.

Are you game? Here goes:

Car:
1972 Demon
4-speed (close ratio gear set)
Rear: 8.75 with 3:55 Sure Grip
Rear Tire: Nitto Drag Radial 275/50-15 (25.75 dia.)
Exhaust: TTI step header and full 2.5" with X-pipe
Speedo pinion: 35
Speedo calibrated by Redline Gauge Works
Highway mpg 15.46
This was a 500 mile trip averaging 60 MPH with normal driving (no drag racing). I stopped every 150-170 miles to top off the tank (because at that point I was down to 1/4 tank) and to give my tailbone a rest. The route was from the east coast of Virginia to Roanoke using two and four lane roads (Rte 5, Rte 106, and Rte 460).

Camshaft - Hydraulic Roller (Cam Motion)
Duration Intake @50 242
Duration Exhaust @50 248
Lift Intake: 570
Lift Exhaust: 562
Lobe Separation: 110
Centerline (Installed): 105.5
Valve Springs (Comp Cams: 994-16)
Rockers: Comp Cams Pro Magnum Roller Rocker Arms, 1.5 ratio
Roller Lifters, 1991 LA 360 Stock

Crankshaft, Cast (Eagle) Internally Balanced, Stroke 4.000”
Pistons (Wiseco, Pro Tru Forged) PN: WISPT036H3
Bore: 4.030
Dish: 20cc
Compression Height: 1.460
Compression Ratio (Based on head gasket that is .039 thick with a 4.180 bore and a piston deck height of .0040)
Static Compression Ratio: 9.84:1
Dynamic Compression Ratio: 8.85:1
Dynamic Cranking Pressure: 179.26 PSI

Heads casting #4448308
Combustion Chamber Volume: 65cc
2.02" Intake (CFM)
1.60" Exhaust (CFM)
Flow: (Intake/Exhaust)
0.100 Lift 64 50 78.12
0.200 Lift 132 98 74.24
0.300 Lift 184 136 73.91
0.400 Lift 226 175 77.43
0.500 Lift 254 189 74.41
0.600 Lift 247 196 79.35

Carburetor (Pro Systems Pro Series - XE)
Holley 4150 HP Main Body
Jets: 75/85
Power Valve: 6.5/plug
Accelerator Pump: 50 cc/30 cc
Vacuum @ 1000 RPM: 11"

Distributor: FBO Mopar Electronic Ignition A688
Initial Timing: 18 Degrees
Total Mechanical @ 3200 RPM 16 Degrees
Vacuum Advance (@ 10 inches) 12 Degrees
Timing set @: 34 Degrees

Engine Dyno results: (with el-cheapo 1-5/8 headers because TTIs wouldn’t fit on dyno)
Peak Torque @ 4100 RPM: 460
Peak horsepower @ 5800 RPM: 443
 
BrianT said:
Sixty five posts in this thread and we've heard about 318s, 340s, 360s, slantys, motorcycles, GMs and Lexus'. We've had all the experts chime in on how to get better gas mileage out of your ***. No one has chimed in on how they are getting such great gas mileage out of their strokers.

The original poster is calling out a couple of specific members who made pretty incredible claims on another thread. Now they are silent...
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x2...
 
caferacerx said:
no, no you cant, not ever going to happen,
no car will get 20 mpg if you have a lead foot,
the laws of physics can not be broken,
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lol-my Stealth gets well over 20mpg (and believe me- I like the boost).


...and it makes about 400hp, so the fact that it's a little v6 doesn't bother me:D
 
so Demon 408 what is your mpg?

I might drive with a lead foot but the little v6 puts out only so much power. I don't go 90 mph on the freeways either--that thing is unsafe at those speeds, lol
 
I think mpg is like et, talk is cheap and again if your speed o is off you can get confused. If you drive around everywhere thinking your going 5 mph faster than your really are--how do you find out?

these newer cars speed o read fast. If your going 70 mph chances are its only 68 mph, those 2 mph can add up
 
LMAO, Now these were entertaining post and a very good sublect, Thanks everybody.
 
fuel economy and speed are always going to be opposite each other THIS IS A FACT it can not be disputed it is physically IMPOSABLE to increase speed without a corresponding increase in energy (or fuel) any 6th grader should knows this, (barring any head wind, tail wind, up grade, or down grade)
now engine efficiency, gearing and other factors DO play a part in fuel economy, meaning there IS a speed range in which your car gets optimum MPG, or more specifically a point where the fuel usage vs speed graph levels out, meaning an increase in speed within this range only produces a small increase in fuel consumption, BUT there IS always an increase in fuel use in order to effect an increase in speed as long as you are traveling on a level surface with no wind,
when ever you get out of that peak efficiency range the amount of fuel needed to increase speed is much more pronounced, it does not matter if you are above or below that speed range, most cars are designed so that the optimum range is around 55MPH to 60MPH
the other HUGE factor with fuel economy vs speed is wind resistance, and wind resistance increases exponentially as speed increases, so you can see there is no way to DECREASE fuel consumption while at the same time INCREASING mph, in order to do that your car would need to put out MORE energy than it takes in, in effect creating a "perpetual motion machine" which any 6th grader will tell you is imposable, if you don't believe me ask one.
new old car truck bike train plane boat bus skateboard bicycle it doesn't matter the laws of physics apply to everything equally and at all time's everywhere for everyone no exceptions EVER! it is a simple fact and it can not be disputed period
if you have a problem with this remember Issac Newton and Albert Einstein were WAY smarter than you will ever be
 
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