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Discussion Starter #1
I'm probably going to start driving my Cougar (4.6L) to and from work (55 miles each way) and I've been "thinking" about something.

Everyone (myself included) usually goes for the performance over fuel economy route. Well I'm thinking about going fuel economy over performance. :beek:

Here is my "plan" and my "goal":

Goal:
35 to 40 mpg highway and 15.0 - 15.9 1/4 mile times :beek:

Plan:
2.73 Traction Lock
Good "Fuel Economy" Tune (Probably from Lonnie)(Must be coded to run on 87 octane)
Modified TC lockup schedules and shifting routines (what I'm thinking is let the transmission shift more to handle the low gear set)
U/D Pulleys
Leave the exhaust as is (all 3 cats and just "resonator tips") to keep the bottom end torque

I've seen people getting 27/28 (My best was 28.5 in my T'Bird when it was stock and had 3.08's) so I'm figuring that 30 - 35 should be "doable" if I keep my foot out of the throttle (which will probably be the hardest part :leftright )

So does anyone have any other thoughts (excluding narrower tires... I'm set on the 235 60 16's that I have on there now). :2huh:
 

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Thinking about wind resistance..........................

Are you lowered already? That will make your frontal profile smaller, and give you a little less resistance. Maybe a front air dam to keep more air out from under the car.

Keep your windows up, don't run the A/C.

Change all the oils to full synthetic, including differential.

Old cars used to have an overdrive that let the car 'freewheel' when you let off the gas. If the TC wasn't locked at highway speeds, would you get that effect? or at least if it unlocked when you took your foot off the gas? I know my Expedition does that, and I HATE it, waiting for it to lock backup after you step on the gas again.
 

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no chance getting anywhere near 40mpg in any tbird, i don't care what you do to it.

Best I ever got was 30.5 on a freeway to carlisle doing about 75-80mph with 3.08 open gears. An open rear is going to give you better gas mileage than a trac loc would.
 

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Discussion Starter #4
JustinH said:
No chance getting anywhere near 40mpg in any tbird, i don't care what you do to it.

Best I ever got was 30.5 on a freeway to Carlisle doing about 75-80mph with 3.08 open gears. An open rear is going to give you better gas mileage than a trac loc would.
Well, I did say 35 to 40... j/k :D

Here's my logic:
1. Keep my foot out of the throttle (I can change the mpg by +- 5, just by driving style)
2. 2.73's might be good for 1 - 2 mpg depending on how hilly the terrain is
3. A good tune nets 2 mpg from what everyone says (and what I've observed with both my chips)(And maybe if the tune is done with fuel economy in mind, then it might even net more)
4. Full synthetics might net me 1 mpg.

And yeah, 40 will be VERY tough to touch! But I think 35 is possible. (Oh and I am ONLY talking about 100% highway driving... :D )

And right now with the 3.73's in my T'Bird I'm getting about 20 mpg. So even if I can add 10 mpg in the Cougar, I'll still be noticeably reducing my monthly fuel bill. :D
 

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don't forget to remove the interior, and scrape all the insulation off, you are going to need every pound in weight savings.

Forget bringing any luggage also :)

Just kidding dude I'm eager to see the results.
 

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I got 35mpg on the way to 2002 MN12Nationals. 3.08 open and 205mm wide tires and this was going both up and down the Blue Ridge Mountains. And none of the lowering crap either.
 

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damn, I need to get a 4.6 for mileage. Even bone stock I never seen better than 26 out of my 3.8L, worst was 22mpg stock. Now with the blower and 3.73's I see ~23highway, ~18 back and forth to work.
 

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Discussion Starter #11
Every 4.6L that I own (T'Bird (SOHC) w/3.73’s, Cougar (SOHC) w/3.08’s, and Mark VIII (DOHC) w/ 3.27’s), I can change the mpg by AT LEAST 5 mpg just by the way I drive. These 4.6L's love to inhale gas at WOT... especially with a stock tune. :beek:
 

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94 Daily Driven 4.6L said:
.....And maybe if the tune is done with fuel economy in mind, then it might even net more
i think a good tune will net you even more......on the 550-some miles to my dyno tune i got about 21.5 mpg, and on the way home i got 25.x mpg........i read that Lonnie has a very good economy tune...... in fact, so good, that he doesnt give out specifics to anyone....so it must be good! :)
 

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guitar maestro said:
and pray one of the rear tires don't blow out and have part of it land on your windshield at 60-some mph :eek:
If it is gonna blow, you better be back some distance anyhow, so I say, THERE SHE BLOWS!! :eek:
 

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Weight is not so much an issue once you are at speed and on the highway you anit stopping much.
You may also want to try and play with the spoiler.
I'd say 35 is do able I've gotten 27mpg in mine with Cruise set at 75mph between Memphis and Jackson. Though I normally see 16-18 in town and 22 highway.
 

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Take the spoiler off if there is one. SCCoA guys tested it and got better MPG with it off.
 

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Makes sense too much down force is too much friction.
 
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