I'd say that's about average. I usually get around 24 with a mix of city and highway. I get up to 27 highway with my 3.27 rear. My friend had a 95 4.6 with a 3.08. He never got more than 20 MPG.

I agree that the stock V8 Thunderbird is dissapointing after you drive one. It definitely has more horsepower than the 3.8, but the 4.6 lacks the torque necessary to push a heavy car. At least the kind of torque that this Ford small block guy has come to expect from a Ford V8. Judging by your user name you probably feel the same way.

 

Lots of 4.6's have 3.27 gears too. Mine does.

 

I noticed that after asking around that my gas mileage is equal to a 4.6. I was told that its because 3.8s have a 3.27 ratio(I knew that) and that 4.6s have a 3.08 ratio. Is that why 4.6s dont seem that much faster? i drove a 96 4.6 and it didnt seem to be as fast as I was expecting. Also, what do most V6s get vs. the 4.6. I usually get between 23 and 25. is that average?

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My best ever was 30.5 all the way to carlisle, PA last year. This year, for some reason I could only get 27-28.

JH

 

Lots of 4.6's have 3.27 gears too. Mine does.

And some 3.8L N/A's have 3.08's, I have a 89 with 3.08's and a T-loc from the factory.

-Rod

 

I have 3.08's, and USED to get 25-29 (highway), but lately I've been getting more like 22 or less . Would putting 3.27's in help my economy? What about power? If upgrading to 3:27's (or higher) would help both my economy and how fast the car gets up and goes, I would consider spending the money to do it... Any input?

Now for a Stupid question... How exactly does the gear ration affect economy and power? My '97 Chevy truck has a 454 and 4.10's, and gets about 11MPg hwy. From what I've heard, the 4.10's are for towing, and 3.73's are more for economy... Is it the higher the ratio, the more torque and less economy?

 

3.27:1 when talking about the differential refers to 3.27 rotations of the drive shaft for every rotation of the differential output (axle shafts.) So 3.27 is lower than 3.08. Think of it like the rear sprocket on a bicycle. When you're on that big cog you have to pedal like crazy to go anywhere, but it's very easy to pedal. When you're cruising along on the smallest cog, it more difficult to pedal, but you only have to pump your legs a fraction as much as you did on the larger cog.

Same deal goes for the differential in a car. Lower gearing makes it easy to move the car, but at the expense of higher RPMs. In some cases, you won't notice much mileage between different gear sets. Say if you moved from 3.27s to 3.73s... you might not notice much mileage difference at all because even though the motor is turning higher revs, it doesn't have to work as hard to move the car.

I don't think gears are going to fix your mileage problem. If the car hasn't been tuned up lately, I'd definitely do that right away, along with changing the O2 sensors and cleaning the MAF. Always better to fix the real problem first than trying to mask it with something else.

 

yeah, 3.27s are an option on the pre 96 V8s... allot may be 3.08 but not all. 96 and 97 have 3.27 standard, so no 96+ are 3.08. If you buy a 94-95 4.6 bird you should look in the door jam to make sure it has 3.27. My buddy has a 95 4.6 with 3.08 while my 3.8 has 3.27 and when we race I will actually take him off the line untill he gets the RPMs up to about 2800 and then he will catch up and pull away easy. we where both dissapointed with the V8 Tbirds off the line performace.

Jake

 

Well... there is something wrong with the car, but I have NO clue what... I've changed the plugs (just put new Motorcraft copper plugs in and it made NO difference from the boch plats I had), wires, coil packs, top O2 sensors, cleaned MAF, '99 GT 4R70W (the original was acting up), and I've been running 89 octane...

 

Yeah, my user name gives it away. Even the original 289 K code got 271hp and 312 lb/ft. Im disappointed that the 4.6s isnt stronger, 205hp is ridiculous, 140 is even worse for a 4k lb car. I think V8 owners should drop a nice 347 stroker in it like I did to my GT. The old Stang still gets 13mpg with the 373 gears lol.

 

I know i have 3.27s in my LX. Im usually turning around 2400 at 75-80mph. And 105 at 3000 of course (damn governor). I dont have T-lock tho. :ztoohot: