advantages of 3.55 rear gears...?

[mrltd]

28" overall diameter? Why?

[87vicFIVEO]

Actually, more like 27.8, why not? I don't think the current tire diameter fills out the rear wheel well enough.

[87vicFIVEO]

I plan to run 275/60/15's out back.

If my calculations are correct, this tire is close to 28 inches in diameter.

[Mr. Land Yacht]

hmm..yea, when my rear shocks are pumped up nice and high, I feel the same way...wish it was about and inch taller...

[Blaze86Vic]

Pure highway mileage will go down. But only a person that drives 80% or more highway will realize that effect overall. I used to get average around 21mpg on pure highway, now I get average 19mpg. But if there is any real portion of city driving you can easily make the difference up. Because I used to average about 16mpg city, where now I average 18mpg. So most all the time I get 18mpg.

[Archangel]

So why does everyone look at me crazy when I tell them I want to run 4.10's in my daily driver???

I plan on running those too, with 29" wheels and over 4200lbs weight and more than 3/4 city driving my Townie can definitely use a set. Also if I'm not mistaken Jeff Boudah absolutely loved his 4.10s in the Crown Vic, and so did Adam (AOD).

4.10s are pretty high for a DD.
for example, at 70pm in OD, I'm revving at about 2200...with 2.73s, it was more like 1800 or so...IIRC.
but with 4.10s and stock wheels, you'll be revving at like 2400-2500...mpg shall die quickly

And that is why you always drive by engine speed, and not vehicle speed - like for my truck I try to keep about 1800-2000rpms steady, it's around 50-55mph with the stock tires, don't care how fast that actually is now with the 33s. In case of a panther with 4.10 you just slow down, if 1800rpms used to be 75mph and with the 4.10s it's now like 60-65 then that's how fast you drive, and our cars are actually big enough and old enough so we can drive slow and not get harassed about it from everyone and heir mom.

[Nathan in MI]

4.10s are pretty high for a DD.
for example, at 70pm in OD, I'm revving at about 2200...with 2.73s, it was more like 1800 or so...IIRC.
but with 4.10s and stock wheels, you'll be revving at like 2400-2500...mpg shall die quickly

Really, 2400-2500 isn't all that unreasonable. My dad's Chrysler had 2.94 gears and no overdrive. That (assuming 26.5" tall tires, which I believe you'll find is the stock height on our cars, and Chryslers used pretty much the same thing) combination at 70 mph was about 2600 rpm. Much faster than a 2.73 panther in OD is running, but it wasn't that bad...and unlike being in OD, you didn't have to kick it down a gear in order to accelerate. Fuel economy was about 19 mpg give or take...2bbl carbureted 318.

[torquelover]

The rough ride is all because of the low profile tires, no question there

Not to mention the unsprung weight increase.

[85MercPark]

My brother has a 96 Roadmaster with the 5.7, damn thing got 30.4 MPG on the trip to Maine. At 70 it was running 1400 rpm. Freakin amazing!!!

[87vicFIVEO]

My brother has a 96 Roadmaster with the 5.7, damn thing got 30.4 MPG on the trip to Maine. At 70 it was running 1400 rpm. Freakin amazing!!!

REALLY

[85MercPark]

I didn't believe him at first, but we used my gps to get our miles traveled and calculated from that.

[87vicFIVEO]

That's amazing.

[Mr. Land Yacht]

yea..that is amazing...wow.
but I remember a guy on here that had a white 88 Merc with LX Sport wheels and tall tires..he got 29 on the hwy once...wow.
you wouldn't think a 4K lb car with a V8 could get that...but I guess when the rpms are turning like 1400...it can happen.

[Archangel]

yea..that is amazing...wow.
but I remember a guy on here that had a white 88 Merc with LX Sport wheels and tall tires..he got 29 on the hwy once...wow.

I've seen 28mpg, running 245/60-15 (so 1.5" smaller than stock) tires and with screwed up aerodynamics (hoodscoop + spare wheel behind the bumper). And yes, that is the correct mileage after I recalculated it for the smaller tires.

[tp8728]

since i put the 3.73 in my merc, my gas changes drastically depending on where i drive it. i drive about 20mi to work and 20mi home the interstate makes up about 15 of that, driving to and from work in one day i use almost a quater tank of gas because at 75 the rpms are really high, i dont have a tac but it is a lot louder. if i take the back roads to work it adds about another 18mi round trip, doing 40-50 i only use 1/8th of a tank round trip. it takes a little longer but its deffinatly cheaper on gas. the acceleration with the factory 2.73 was horrible after my wheels and system, the merk didnt want to move at all, but with the 3.73 in, i let off the brake and she starts moving, if i step on it she takes off nicely. if i could re do i would probably to a 3.55 just for the highway milage, but i like the way it is now.