Would Gears Help?
03-24-2006, 08:35 PM
#11
2nd Gear Member
Join Date: Oct 2005
Location: Frederick, Md
Posts: 245
RE: Would Gears Help?
hey woody, listen to everyone, but dont worry about what anyone else says in any thread that chevykiller, hawgman or sypder2274 answer in. they know there **** and pretty well explain every angle....
now to answer your question about if it hurts your car. just look in your owners manual and ford RECOMMENDS shifting into 5th gear at 40mph for best mileage. now im not the sharpest knife in our forum drawer, but i did dress up as captain obvious for halloween. if ford is telling you to shift at 40mph to get there rated fuel mileage then you can trust them they built the car...
now to answer your question about if it hurts your car. just look in your owners manual and ford RECOMMENDS shifting into 5th gear at 40mph for best mileage. now im not the sharpest knife in our forum drawer, but i did dress up as captain obvious for halloween. if ford is telling you to shift at 40mph to get there rated fuel mileage then you can trust them they built the car...
03-24-2006, 10:05 PM
#12
I ♥ Acer
Join Date: Jan 2006
Location:
Posts: 619
RE: Would Gears Help?
ORIGINAL: woodywoody
Ok, so I have an 06 GT. I don't really speed when I drive. I only go about 5-8 over the speed limit. I drive on 45 and 35 MPH roads on my way to work. I stay in 4th gear all the time at about 2400rpm. My average gas usage is 15.7 miles per gallon. When i move into 5th gear to reduce the RPM and save gas (keep in mind i am only going around 50-53mph), the car seems very... slugish. I feel like i am hurting it. The rpm's are around 1350-1450. Seems like you need at least 1600+rpm in those high gears to move the car without feeling like it not hurting something.
So I was thinking about getting some gears. So when I shift into 5th gear it will be well above the 1350-1450 it is now. I was looking to be at like 1650-1700 RPM. Would I need 3.73, 3.90 or 4.10? I don't do much of any highway driving, only city. Any ideas?
-W
Ok, so I have an 06 GT. I don't really speed when I drive. I only go about 5-8 over the speed limit. I drive on 45 and 35 MPH roads on my way to work. I stay in 4th gear all the time at about 2400rpm. My average gas usage is 15.7 miles per gallon. When i move into 5th gear to reduce the RPM and save gas (keep in mind i am only going around 50-53mph), the car seems very... slugish. I feel like i am hurting it. The rpm's are around 1350-1450. Seems like you need at least 1600+rpm in those high gears to move the car without feeling like it not hurting something.
So I was thinking about getting some gears. So when I shift into 5th gear it will be well above the 1350-1450 it is now. I was looking to be at like 1650-1700 RPM. Would I need 3.73, 3.90 or 4.10? I don't do much of any highway driving, only city. Any ideas?
-W
The easiest thing you can do and save yourself some $$$$ at the same time, is to just not use OD. Your 4th gear is a 1:1 ratio, so that would be like having an old car back in the 50's-70's with a 3.55 rear end.
Even with my 3.73s and my automatic, if I know I will be under 45mph, I turn OD off using the **** on the shifter.
One other thing you can consider doing when you use 4th gear is to get yourself some larger diameter wheels and tires. That will drop your revs in 4th and OD on the highway as well.
03-25-2006, 03:19 AM
#13
2nd Gear Member
Thread Starter
Join Date: Feb 2006
Posts: 267
RE: Would Gears Help?
All i know is when i shift into 5th gear going anywhere under 55mph it's not good for the car. Again, anyone out there with a 5speed like me, just go ahead and shift into 5th gear going 40mph like the manual says and see how far you get. I shifted into 5th tonight to show a friend who was riding with me while was going 50mph and he was like "Wow, thats crazy... Is that good for the car?" I just want to know what will bring from the 1450 RPM it's at now going around 53mph in 5th to 1600-1750rpm in 5th going 53mph.
-W
-W
03-25-2006, 10:27 AM
#14
5th Gear Member
Join Date: Mar 2006
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Posts: 2,544
RE: Would Gears Help?
ORIGINAL: woodywoody
I just want to know what will bring from the 1450 RPM it's at now going around 53mph in 5th to 1600-1750rpm in 5th going 53mph.
-W
I just want to know what will bring from the 1450 RPM it's at now going around 53mph in 5th to 1600-1750rpm in 5th going 53mph.
-W
So, if your'e doing 1450 RPM now (with the stock 3.55s) and you switch to 4.10s, you'll be doing 1450 x 1.155 = 1675 RPM at that same speed. It seems like 4.10s are what you want!
Though, I still am not sure I see what the problem is. I drive my 5-speed manual GT every day on 35 and 40 mph city streets--in 5th gear. The car is completely stock. The only time I have the "vibration" you describe is if I try to slam on the gas while in 5th at those speeds....but why do that? So long as you're maintaining constant speed on level ground there's no reason not to drive in 5th. The vibration only happens when you accellerate or have to climb a hill. So, cruise in 5th for the mileage and whenever you need to, just downshift to accelerate.
03-25-2006, 10:29 AM
#15
I ♥ Acer
Join Date: Jan 2006
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Posts: 619
RE: Would Gears Help?
ORIGINAL: woodywoody
All i know is when i shift into 5th gear going anywhere under 55mph it's not good for the car. Again, anyone out there with a 5speed like me, just go ahead and shift into 5th gear going 40mph like the manual says and see how far you get. I shifted into 5th tonight to show a friend who was riding with me while was going 50mph and he was like "Wow, thats crazy... Is that good for the car?" I just want to know what will bring from the 1450 RPM it's at now going around 53mph in 5th to 1600-1750rpm in 5th going 53mph.
-W
All i know is when i shift into 5th gear going anywhere under 55mph it's not good for the car. Again, anyone out there with a 5speed like me, just go ahead and shift into 5th gear going 40mph like the manual says and see how far you get. I shifted into 5th tonight to show a friend who was riding with me while was going 50mph and he was like "Wow, thats crazy... Is that good for the car?" I just want to know what will bring from the 1450 RPM it's at now going around 53mph in 5th to 1600-1750rpm in 5th going 53mph.
-W
Here are your answers:
(1750/1450)*3.55 = 4.28 so a 4.30 rearend would raise your rpm to 1750 at 50mph.
(1600/1450)*3.55 = 3.91 so a 3.90 rearend would raise your rpm to 1600 at 50mph.
(4.10/3.55)*1450 = 1675rpm so a 4.10 rearend would raise your rpm to 1675 at 50 mph.
If I were you, I'd pick the 4.10.
Hope this helps.
Mike
03-25-2006, 01:49 PM
#16
2nd Gear Member
Thread Starter
Join Date: Feb 2006
Posts: 267
RE: Would Gears Help?
Yea see thats the problem. The road I take to work and really the whole road around town is very up and down. The only level part of it is te top of the hills before you go back down again. Most of my driving to work is done on these roads so i just need to get 4.10 gears. Plus, i wanted gears anyway but did not want to pay the install cost so this is a way justify getting them in my head. Thanks for the info guys! You rock as always.
-W
-W
03-25-2006, 03:22 PM
#17
5th Gear Member
Join Date: Mar 2006
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Posts: 2,544
RE: Would Gears Help?
ORIGINAL: woodywoody
Yea see thats the problem. The road I take to work and really the whole road around town is very up and down. The only level part of it is te top of the hills before you go back down again.
Yea see thats the problem. The road I take to work and really the whole road around town is very up and down. The only level part of it is te top of the hills before you go back down again.
03-26-2006, 01:24 AM
#19
4th Gear Member
Join Date: Nov 2005
Location: Northern VA
Posts: 1,249
RE: Would Gears Help?
Ok here is a Microsoft Excel Spreedsheet that will calculate the Speed vs RPM for gear sizes entered.
RPM_vs_Speed.xls Spread Sheet
RPM_vs_Speed.xls Spread Sheet
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