If im running a 26" tall tire would there be an ideal set of gears for a daily driver who really doesnt want to effect gas milage and still wants a good gear for good street use??
Does tire size effect gears?
- Thread starter jstang209
- Start date
Tonys96Cobra
professional deer "mounter"
I always recomend 3.55 for a DD, but I guess it depends on how long your commute is. You could go 3.73 also, but if it were me, Id do 3.55.....just my $.02
Yes tire size does affect gearing. Stock tire size is 25.6" so a 26" tall tire shouldn't affect it much. Taller than stock tires lower gearing slightly while smaller tires increase gearing.
3.73 is the ideal all around gear for a Foxbody Mustang 5.0.
3.55's just won't quite cut it, and 4.10's seem to be a little too steep on a street driven, bolt on 5.0 motor due to the powerband and weight. However, if you do a lot of racing at the track on slicks, 4.30 would be ideal, but 4.10 would be a compromise for the street.
The fact is that a 3.55, 3.73 and a 4.10 are only a couple hundred rpm apart in 5th gear (OD in an auto) but in the lower gears it is vastly different. If you do the math, you'll see why.
First gear differences: (stock T-5 first gear x diff gear = final drive ratio)
3.35 x 3.55 = 11.89
3.35 x 3.73 = 12.49
3.35 x 4.10 = 13.73
Fith gear differences: (stock T-5 fith gear x diff gear = final drive ratio)
0.68 x 3.55 = 2.41
0.68 x 3.73 = 2.53
0.68 x 4.10 = 2.78
So as you can see, the difference in 5th gear isn't that much, just a couple tenths, but in first gear it's a world of difference, whole digits.
3.55's just won't quite cut it, and 4.10's seem to be a little too steep on a street driven, bolt on 5.0 motor due to the powerband and weight. However, if you do a lot of racing at the track on slicks, 4.30 would be ideal, but 4.10 would be a compromise for the street.
The fact is that a 3.55, 3.73 and a 4.10 are only a couple hundred rpm apart in 5th gear (OD in an auto) but in the lower gears it is vastly different. If you do the math, you'll see why.
First gear differences: (stock T-5 first gear x diff gear = final drive ratio)
3.35 x 3.55 = 11.89
3.35 x 3.73 = 12.49
3.35 x 4.10 = 13.73
Fith gear differences: (stock T-5 fith gear x diff gear = final drive ratio)
0.68 x 3.55 = 2.41
0.68 x 3.73 = 2.53
0.68 x 4.10 = 2.78
So as you can see, the difference in 5th gear isn't that much, just a couple tenths, but in first gear it's a world of difference, whole digits.
oops, forgot...
Tire size definatly effects final drive ratio. A 26" is similar to factory size, but on a 28" tire, you'll need to go up one step, because a 4.10 on a 28" will behave like a 3.73 on a 26".
Tire size definatly effects final drive ratio. A 26" is similar to factory size, but on a 28" tire, you'll need to go up one step, because a 4.10 on a 28" will behave like a 3.73 on a 26".
ninety15.0
New Member
- Mar 10, 2004
- 1,336
- 0
- 0
yea the stock tire is 25.74 inches...so a 26 inch tires is for all intensive purposes stock size. Honestly i would reccomend 3.55's for a stockish daily driver. I have 3.73's with stock tire size and i can honestly say i wish i could cruize at a slightly lower rpm on the highway. go to this website and you can figure out every configuration possible. http://www.corral.net/tech/gearcalc.html
good luck man
good luck man
stangjunkie
New Member
- Nov 15, 2004
- 381
- 0
- 0
not to threadjack... but if i wanna have a different set of tires for the track i should run a smaller tire to simulate a lower gear ratio... right?? or wait thats backwards?? im confused...
Does someone have a good write up on the math of the final drive, gears, tires etc...
Does someone have a good write up on the math of the final drive, gears, tires etc...
Michael Yount
Mustang Master
Stangjunkie - you're right -- a SHORTER tire makes the car think it has more gear; TALLER tire works the opposite.
ninety15.0 - "...intensive purposes..." -- never heard it put that way before.
The phrase is 'for all intents and purposes'....
ninety15.0 - "...intensive purposes..." -- never heard it put that way before.
The phrase is 'for all intents and purposes'....
50bomber
New Member
Man you people must work for tire stores of manufacturers!
The first gear on a 3:73 car is waaaaaay too short for daily drivers, and that's with my T5-Z, which has higher(or is it lower Micheal?) 2.95 first gear, it still pretty much strips the thread of the tires on any spirited take off! Maybe for drag racing, when you wanta buzz the engine into the powerband, but on the street its the pits, when you have two change to second halfway through the intersection. On the other hand, it is perfect for AOD cars, which have taller first gear, like a 2.4, which my car had before I changed over to T-5, hence why I got in the first place, otherwise I would have gone with 3:55....But that's my story, and I am sticking to it!! I may be wrong, but I don't think so
:SNSign: .
The first gear on a 3:73 car is waaaaaay too short for daily drivers, and that's with my T5-Z, which has higher(or is it lower Micheal?) 2.95 first gear, it still pretty much strips the thread of the tires on any spirited take off! Maybe for drag racing, when you wanta buzz the engine into the powerband, but on the street its the pits, when you have two change to second halfway through the intersection. On the other hand, it is perfect for AOD cars, which have taller first gear, like a 2.4, which my car had before I changed over to T-5, hence why I got in the first place, otherwise I would have gone with 3:55....But that's my story, and I am sticking to it!! I may be wrong, but I don't think so :SNSign: .
302RollinHard
New Member
4.10's, these gears are much to short.
2.73's, these gears are much too long.
3.55's, these gears are Just Right.
2.73's, these gears are much too long.
3.55's, these gears are Just Right.
,I still have 3.08`s,so I can only imagine how fast first gear is gone in a flash with 3.55 gears and up.
50bomber
New Member
I think my 92 honda accord has a numerically higher final drive ratio than my 3.73 mustang does. If it can do it, why can't my mustang?
A taller gear is not a way to solve traction issues. 50Bomber has some suspension mods, but tight springs, and this will effect traction. IMO, suggesting a 3.55 over a 3.73 for traction issues is the same as suggesting a weaker motor for traction issues. Traction is in the tires and suspension, theny need building too.
Euphoric306
New Member
- Apr 5, 2004
- 905
- 0
- 0
agreed with 90 mustanggt
do some suspension mods, specifically lca's, uca's and springs/shocks/struts (if yours are worn out or money isn't too big of an issue) and even on a stock tire the difference is amazing.
having that said...
for a 17" rim, and the stock tire height (something like 275/45?) youi're saying that the tire i see in those pictures is 4" on top and bottom of the tire? 17 + 4 + 4 = 25
it may be mathematically correct, but all the pics i see on here with 17" wheels do not look lik the tire is anything over 2.5" high (profile)
or are you people just running smaller than stock tire height?
do some suspension mods, specifically lca's, uca's and springs/shocks/struts (if yours are worn out or money isn't too big of an issue) and even on a stock tire the difference is amazing.
having that said...
for a 17" rim, and the stock tire height (something like 275/45?) youi're saying that the tire i see in those pictures is 4" on top and bottom of the tire? 17 + 4 + 4 = 25
it may be mathematically correct, but all the pics i see on here with 17" wheels do not look lik the tire is anything over 2.5" high (profile)
or are you people just running smaller than stock tire height?
Stock tire hight for a Mustang is 25.7 (give or take a 1/10th due to tread)
225/60R15
235/55R16
255/50R16
245/45R17
275/40R17
315/35R17
335/30R17
285/30R18
These are all 25.6-25.7" tall tires. However, the amount of sidewall is a different story.
Let my experience prevent you from making mistakes. I had a set of 225/60R15 Futura Sport GLH (pepboys)on the stock 15x7 turbines and I could hook a 1.9 60ft. Swapped out to a 275/40R17 Futura Super Sports on 17x9 cobra R's (245/45's up front) and I expected to really stick because they were nearly twice as wide in the rear. Wrong, I couldn't break below 2.0 60's at the track, and street traction wasn't much better either. Drove a lot better though. I put on some Nitto DR's and that made a HUGE difference on the street, but only a 1.8 60ft, but usually a 1.9 60ft. I did full drag suspension (UCA, LCA, springs, struts shocks) and it didn't help a bit, found out it was a worn out traction-loc, rebuilt it, and then I was hooking low 1.8's consistantly, but never could break into 1.7's. There was just not enough sidewall in the tire to dig in so I could even use the suspension. I sold the Cobra R's and now have Welds with ET streets, but can't try it out yet. I have 3.73 FMS gear. I'll say this though, the street traction was damn good. Nothing beats the look on a AWD Eclipse, WRX, or EVO driver's face when he 5K launches on you and your still next to him.
225/60R15
235/55R16
255/50R16
245/45R17
275/40R17
315/35R17
335/30R17
285/30R18
These are all 25.6-25.7" tall tires. However, the amount of sidewall is a different story.
Let my experience prevent you from making mistakes. I had a set of 225/60R15 Futura Sport GLH (pepboys)on the stock 15x7 turbines and I could hook a 1.9 60ft. Swapped out to a 275/40R17 Futura Super Sports on 17x9 cobra R's (245/45's up front) and I expected to really stick because they were nearly twice as wide in the rear. Wrong, I couldn't break below 2.0 60's at the track, and street traction wasn't much better either. Drove a lot better though. I put on some Nitto DR's and that made a HUGE difference on the street, but only a 1.8 60ft, but usually a 1.9 60ft. I did full drag suspension (UCA, LCA, springs, struts shocks) and it didn't help a bit, found out it was a worn out traction-loc, rebuilt it, and then I was hooking low 1.8's consistantly, but never could break into 1.7's. There was just not enough sidewall in the tire to dig in so I could even use the suspension. I sold the Cobra R's and now have Welds with ET streets, but can't try it out yet. I have 3.73 FMS gear. I'll say this though, the street traction was damn good. Nothing beats the look on a AWD Eclipse, WRX, or EVO driver's face when he 5K launches on you and your still next to him.
I think Jstang is running 20's, so he might want to consider running 3.73's or 4.10's to compensate for the extra rotational weight of the wheels
Similar threads
