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Just currious if my spedo is off. Someone said at 60 their RPM was 1500 when in 6th.

Mine is runs at 1350 at 60 in my 2010 RT.

Can someone please concur, I have 18" Michelins on my RT
 

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Do you have 3.73's or 3.92's? That might cause a difference. 6 speed's don't use 3.06's (that's auto)
 

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Under the 6 Speed manual Transmission in the Optional Equipment section of my window Sticker it says 3.73 Rear Axle Ratio
That's why. The 3.92's is a short gear ratio, so at higher speeds would be higher. Theoretically you should get better gas mileage with your 3.73's.
 

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Under the 6 Speed manual Transmission in the Optional Equipment section of my window Sticker it says 3.73 Rear Axle Ratio
Ahhhhhh there you go man, those 3.73's are giving you a lower cruising rpm. I was a little off, thought you had an auto. I just drove mine with 3.92 and it was right at 1500 @ 60
 

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Ahhhhhh there you go man, those 3.73's are giving you a lower cruising rpm. I was a little off, thought you had an auto. I just drove mine with 3.92 and it was right at 1500 @ 60
As I recall the manual has a 3.73 with 18" wheels and a 3.92 with 20" wheels.

Note how 393/373 = 1.054 and 1500/1350 = 1.111 but then also consider inaccuracy in the tacho and the radius difference between the 18's and 20's (I don't know the actual difference in radius, but it isn't a lot)
 

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As I recall the manual has a 3.73 with 18" wheels and a 3.92 with 20" wheels.

Note how 393/373 = 1.054 and 1500/1350 = 1.111 but then also consider inaccuracy in the tacho and the radius difference between the 18's and 20's (I don't know the actual difference in radius, but it isn't a lot)
Yeah thats right, he's got a manual with 18's with 3.73. I have a manual with 20's with 3.92.
 

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I believe that if you measure from the ground to the top of the tire, the 18" and 20" will be the same. The circumference of the wheel and tire combination will be the same. The 20" wheels have a lower profile tire than the 18" wheels.
 

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Just currious if my spedo is off. Someone said at 60 their RPM was 1500 when in 6th.

Mine is runs at 1350 at 60 in my 2010 RT.

Can someone please concur, I have 18" Michelins on my RT
My car is right at 1400rpm @ 60 mph. I have the stock wheels/tires (20" classic's with Goodyear RS-A's)
 

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I have the Rt 6 speed with 3.73 and my RPM in 6th gear runs around 1500. I noticed in the pic that your low air pressure light was on, you might want to check those tires.
 

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My car is right at 1400rpm @ 60 mph. I have the stock wheels/tires (20" classic's with Goodyear RS-A's)
Me too.

Regarding the different wheels/tire combos, I would bet Dodge keeps the overall height and cirucumference the same. I seriously doubt they have different calibrated speedos for these cars depending on your tire selection.

Mazda had a calculator on their Miata website I used many years ago. You can play with it, enter in a stock tire dimension, then what you are considering and see how it affects you MPH displayed. There are many, many combinations of wheels and tires that give exactly the same MPH reaading, you just have to make the profile of the tire smaller as you go up in wheel size.
 
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