Has anyone here ever experimented with using 2.73:1 rear gears? Seeing how some S197 GTs can get nearly 30 MPG on the highway using stock 3.31s or 3.55s, it'd be interesting to see how much better MPGs they can get with 2.73s. Sure, you'd sacrifice acceleration but it'd be impressive to drive a 300 hp muscle car that also gets 40 MPG on the highway.

 

A muscle car is supposed to be able to pull off the line, I think you'll be sacrificing A LOT of what makes a muscle car a muscle car.

I posted the question a while ago as to why can't we change 5th gear, make it a .45 to .5, that way you can install 4.10s for 1st through 4th gear, and cruise with a 40mpg mustang on the highway. I'm still curious as to why NOBODY answered that question yet. I have to stop by my mechanic's place today, so I'll ask him about it. I'll post what I hear, in the meantime, anybody has any thoughts on this?

 

These cars do not have the low end torque that the old 302 had, plus they weigh alot more so this car would be a total turd with 2.73's. I bet that is why Ford has never offered them in these cars.

 

My 4100 lb Crown Vic with the 4.6 2V came with optional 3.55s, but 2.73s were standard. The 2.73 Vics will get up to 30 MPG on the highway, while the 3.55s only net 20-21 MPG.

 

That'd be my guess. Our Vette has 2.73's in it but the LS1 has enough torque down low that we're still running 12.8's@110mph even w/ the crap gears. That's the first thing I noticed when I picked up the Mustang...the different powerband characteristics. The LS1 pulls in a very linear way, harder outta the gate than the Mustang and continuing to increase in pull. The 4.6 3V seems 'OK' down low but doesn't really start to pull until 3000-3500rpm.

 

How about a six speed trans swap? The Richmond ROD six speed

That way you could get a .52 sixth gear.

The only problem is that it's expensive.

 

Good luck with that. While you're at it you could probably find someone somewhere to de-tune the 4.6 and get even more mileage. Take it down from 300HP and I would bet your miles goes up.

Then again, if you bought a V8 muscle car with 300HP and expected great gas mileage you have bought the wrong car.

 

I consider 30mpg a great gas mileage, fact is that's what I got often in my 89LX 5.0 on the highway (gotten as much as 33mpg @ 100mph cruise controled!). I don't think buying a muscle car immediately means you can't have good gas mileage.

The 6 speed trans, I've asked that questions and started a thread ages ago:

http://forums.bradbarnett.net/showth...nsmission+swap

Lots of threads on transmission swaps, just search...

Still, lots of views and some replies and nobody makes a comment about replacing 5th gear in the transmission. It's been done with other cars, why not ours?

 

I agree, every naturally aspirated modular V8 that I've driven is a slug below 3000-4000 RPM. With the 4.6L 3V V8 and the TR-3650, you can definitely FEEL the lack of power below 3000 RPM. Once you hit 3000, the best way to describe it is by saying "I can feel the V-TEC kicking in" because the car suddenly starts to pull harder. I suppose this is more noticeable due to either the VCT or clutch or a combination of both compared to the 4.6/5.4 2V/4V without the VCT and with an automatic (torque converter slippage).

I get about 22-24 MPG in combined city/highway driving.

 

Wait a second, the SN95 in 1996 had 2.73 gears standard with a 4.6 and only 215HP.
Not the fastest car, but it was not slow and is very drivable.
The point is that it can be done and it would increase highway MPGs.

 

Dang Ive got gears, lower profile tires, intake, full exhaust and am consistantly pulling off 17mpgs around town and 23-24 highway

 

I confess that I didn't buy my 07 GT (with 3.55 rear) convertible for mileage but I did get up to 26 mpg with the cruise on at 65 mph. I also got up to 30.1 mpg on my wife's Grand Marquis (with 2.73) under the same circumstances which, I thought was a real achievement for a car of that size so there is no doubt that the gears can make a huge difference.