What drivetrain would you put in for 30 mpg?

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TURNA

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Jul 24, 2009
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online170

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Oct 28, 2010
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And what kind of mileage do you yourself get, by the way? o_O

Stories people find hard to swallow always seem to be about someone other than the person telling the story.

I'll double-check your calculations later. :p

I guess this stuff is so unbelievable that the Only thing left to go after me right?

Im not really "in" the hobby at the moment, due to other life priorities, but;

84 Regal = 12.5 mpg (94otcane with additive ~97-98 octane). If i wanted mileage out of this thing, i wouldn't have a 500+ci big block with 3.73 gears and no overdrive.

Malibu Wagon = 20 mpg (87 octane). 355/T5 with 4.11 gears and 27" tires. Again, the purpose of this car is not to drive on the street, otherwise the mileage would be a bit better. 30mpg is doable with this combination. Currently its optimized for burnouts.

Before that (no longer owned);
71 Skylark = 350-2bbl (87 octane), TH350, 2.73 gears, 28" tires. 25mpg city, 17mpg highway. Thats not a mistake. Upgraded to 4bbl (Holley 750DP and TA intake), gained 30hp, but mileage went to 15 mpg and stayed there.

87 Firebird = 355/T56 (87 octane), 3.42 gears, 27" tires. 34mpg highway, and 20 with mixed driving.

My secret to the last two cars was timing. The skylark was 28* initial, and the firebird was 24* initial timing. All-in as early as it could handle it. And obviously the T56. Most cars from the 90s with T56 and 5.7L engines will do 30mpg. If you can build a gen1 small block to have a similar torque figure below 5252rpm, you can get similar results.



What are you gonna ask for next? A data-logging file from the night of January 16th? Oil analysis report? A urine sample maybe?
 

online170

G-Body Guru
Oct 28, 2010
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A 350 chevy with TPI pulling a 2.05 rear gear (.5 O/D T56) @ 60mph could get 30mpg. A 350 chevy with AFR heads and 4.11 gears that only runs 98 in the 1/4 mile is not making a lot of upper end HP, which means if could be making a lot of torque at 1500 Rpm.

Bingo!

Exotic swaps are cool and all. But $10,000 worth of parts can buy you many gallons of fuel. An SBC can achieve 30+mpg on the freeway no problem, the technology is there. If you want 30mpg all the time, even in city, well my 2.0L ford focus wont even do that. Perhaphs consider getting out of the hobby.

If all else fails you can call me liar from behind your keyboard. LOL
 

TURNA

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Jul 24, 2009
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[QUOTE="online170, post: 561478, member: 7670"
84 Regal = 12.5 mpg (94otcane with additive ~97-98 octane). /QUOTE]


What state are you in? We lost the 94 octane from Sunoco about 10 years ago.
 

axisg

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Jul 17, 2007
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YYZ
[QUOTE="online170, post: 561478, member: 7670"
84 Regal = 12.5 mpg (94otcane with additive ~97-98 octane). /QUOTE]


What state are you in? We lost the 94 octane from Sunoco about 10 years ago.

LOL its in his sig. Ottawa Ontario. We can get 94 at Husky \ Petrocan Stations and 93 at Esso. We can still get some ethanol free fuel at some stations as well.

With the currency exchange being the way it is it may be time for a trip across the border for some beer, fuel, and Cuban cigars... hmm I smell a business opportunity.
 

UNGN

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Sep 6, 2016
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Don't know about a current Corvette, but the 2002 vettes have a dc of .29 which is better than a g body.

C4 vettes with moon hubcaps might have a .29 Cd but actual 2002 vettes don't (maybe a small scale plastic model of one did without mirrors or scoops or hood gaps):

C5-Z06frontendlift.jpg


At speed its almost as high as my jacked up miata. C4 were the most aero. The C5 were styled, the c6's went back to Aero, the C7's were styled, with all of the aero in downforce.

Stock C6 ZO6's (505Hp) (aero) run about the same as C7 Z06's (650HP) (styled, with downforce) in the standing mile and are only about 6 Mph faster than Stock, '94 405Hp ZR1's...with nearly 250 more Hp.

If a stock C4 had a stock C7 Z06 motor, it would be at least 10mph faster in the standing mile than a C7 Z06, weighing the same.

Chevy won't post a Cd number for the C7, but it has to be well over .4

A1000lb heavier Hellcat Charger will run away from a C7 Z06 above 120 mph. 57 more Hp isn't why.
 
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jiho

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I guess this stuff is so unbelievable that the Only thing left to go after me right?

What are you gonna ask for next? A data-logging file from the night of January 16th? Oil analysis report? A urine sample maybe?

Touchy! :D

But you didn't answer about the gasoline, 100% versus E10 or E15 or whatever. It seems that in and of itself can make a surprising difference in mileage.

EDIT: I see from axisg that 100% is available but hard to find.
 
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jiho

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I'm coming due for a urine test at work, I might need the urine. :banana:

Not from him, by the sound of it. Blend yours and his so you'll fail everything at once. :p
 

pontiacgp

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Mar 31, 2006
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In these cars real gas will give you better fuel economy than an ethanol blend. The real gas will also make your engine run better. My SBC 355 roller with a .68 5th gear and 3.08 rear end will get me 26.8 mpg on the highway at 65 mph. I should check it again this year because back then I was using 10% ethanol fuel and I was about 50 lbs heavier than I am now.
 
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