Gears and Wheels Help
07-27-2017, 11:43 PM
#1
Gears and Wheels Help
Hello first of all I'm new here so I'm so sorry if this has been posted before if so please redirect me I have been looking all over the internet for this
I have 20 inch wheels on my 05 V6 now my speedometer is off by some Im not getting into the exact number but it increases as you go faster all the way up to 5 mph off so if it says 50 I'm actually doing 55. Now my RPMs on highway are way lower because once I get into my higher speeds the bigger wheels do their thing I have lower than normal rpms now here is the QUESTION. If I get 4:10 gears for my mustang V6 = increased rpms but if my rpms are already lowered does that mean that I will end up with normal rpms?
For my first mods ever I'm thinking about getting a limited slip differential and 4:10 gears. But I don't know if go down to 17 inch wheels or keep the 20"S
Right after that I will get an sct tuner to fix my rpms and my speedometer and throw a tune in maybe. probably won't until I Get a CAI and Cat back exhaust mods then I will throw in a tune but just answer my question I got carried away thank you
P.S. I don't care about my top speed I care about my acceleration I know all 4:10 gears benefits and drawbacks. Just don't know if I should keep my 20" to help me on highway and higher speeds or should I go back to 17?
Thank you guys and hope y'all having a nice day
I have 20 inch wheels on my 05 V6 now my speedometer is off by some Im not getting into the exact number but it increases as you go faster all the way up to 5 mph off so if it says 50 I'm actually doing 55. Now my RPMs on highway are way lower because once I get into my higher speeds the bigger wheels do their thing I have lower than normal rpms now here is the QUESTION. If I get 4:10 gears for my mustang V6 = increased rpms but if my rpms are already lowered does that mean that I will end up with normal rpms?
For my first mods ever I'm thinking about getting a limited slip differential and 4:10 gears. But I don't know if go down to 17 inch wheels or keep the 20"S
Right after that I will get an sct tuner to fix my rpms and my speedometer and throw a tune in maybe. probably won't until I Get a CAI and Cat back exhaust mods then I will throw in a tune but just answer my question I got carried away thank you
P.S. I don't care about my top speed I care about my acceleration I know all 4:10 gears benefits and drawbacks. Just don't know if I should keep my 20" to help me on highway and higher speeds or should I go back to 17?
Thank you guys and hope y'all having a nice day
07-28-2017, 12:42 AM
#2
3rd Gear Member
Join Date: Jul 2017
Location: AZ
Posts: 849
Hello first of all I'm new here so I'm so sorry if this has been posted before if so please redirect me I have been looking all over the internet for this
I have 20 inch wheels on my 05 V6 now my speedometer is off by some Im not getting into the exact number but it increases as you go faster all the way up to 5 mph off so if it says 50 I'm actually doing 55. Now my RPMs on highway are way lower because once I get into my higher speeds the bigger wheels do their thing I have lower than normal rpms now here is the QUESTION. If I get 4:10 gears for my mustang V6 = increased rpms but if my rpms are already lowered does that mean that I will end up with normal rpms?
For my first mods ever I'm thinking about getting a limited slip differential and 4:10 gears. But I don't know if go down to 17 inch wheels or keep the 20"S
Right after that I will get an sct tuner to fix my rpms and my speedometer and throw a tune in maybe. probably won't until I Get a CAI and Cat back exhaust mods then I will throw in a tune but just answer my question I got carried away thank you
P.S. I don't care about my top speed I care about my acceleration I know all 4:10 gears benefits and drawbacks. Just don't know if I should keep my 20" to help me on highway and higher speeds or should I go back to 17?
Thank you guys and hope y'all having a nice day
I have 20 inch wheels on my 05 V6 now my speedometer is off by some Im not getting into the exact number but it increases as you go faster all the way up to 5 mph off so if it says 50 I'm actually doing 55. Now my RPMs on highway are way lower because once I get into my higher speeds the bigger wheels do their thing I have lower than normal rpms now here is the QUESTION. If I get 4:10 gears for my mustang V6 = increased rpms but if my rpms are already lowered does that mean that I will end up with normal rpms?
For my first mods ever I'm thinking about getting a limited slip differential and 4:10 gears. But I don't know if go down to 17 inch wheels or keep the 20"S
Right after that I will get an sct tuner to fix my rpms and my speedometer and throw a tune in maybe. probably won't until I Get a CAI and Cat back exhaust mods then I will throw in a tune but just answer my question I got carried away thank you
P.S. I don't care about my top speed I care about my acceleration I know all 4:10 gears benefits and drawbacks. Just don't know if I should keep my 20" to help me on highway and higher speeds or should I go back to 17?
Thank you guys and hope y'all having a nice day
The wheel size is important, of course. However, by carefully choosing an appropriate "aspect ratio", fancy wording meaning how wide the sidewall is compared to the tread width, you can usually come up with a "rolling diameter" for the tire which is close to the original stock factory tires. Then your speedometer/odometer will indicate correctly.
For example, my car called for 235-75-15 tires, but I had 16 inch rims I wanted to use. I found that a 245-70-16 was very close to the needed diameter, so I bought those.
Too late in the day here for me now, if you want to know how to predict speedometer error vs. tire size, please ask, and I'll post tomorrow how I do it. Simple, really, no GUESSWORK! imp
07-28-2017, 07:21 AM
#3
I heard of that before. 215=width 65 =sidewalk ratio r16 = rims size what my mustang originally had was 215/65/16 all around now it has 255/45r20 in the back and 245/45r20 in the front I really don't think these has the same diameter I don't think the rim by itself has the same diameter I bet that stuff works with a couple inches bigger let's say I put a 17 or 18 inch but 20 is pretty hard to find the same diameter with I would end up having like no sidewall at all and like that feeling every single bump on the road like it does it enough already plus when it comes to wheels I want them to race not for looks. I would like to have like 17x9.5 or 10 in the back and 17x9 in the front but that's gonna be in the long run I won't change my wheels until these tires wear out because they are brand new Goodyear Eagle F1. Just indecisive if after 4:10 gears not right away but in the long long run should go down to 17. I don't mind smaller wheels as long as they are really wide which are hard to find used or for cheap price. Has you or anyone else installed 4:10 gears on your mustang V6?
