bclexus

It would have made no difference which Drive Mode you were in - it would be the same in ECO mode. At WOT the engine performs the same in all drive modes.

I think you were mistaken which gear you were in, because at 6,000 RPMs in 7th gear your speed would have been 193.9260811252243 MPH. At 6,000 RPMs in 6th gear your speed would have been 159.7950908471848.


Below are ground speeds at 6,500 RPM engine redline for all 6 gears (2013 - 2014) RWD - A760E 6-Speed Automatic:
(*Speed limiter is electronically governed at 142 MPH preventing max speed of ~170 MPH · **Engine will not reach redline in 5th or 6th gear)

1st Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 3.615
1st Gear Ratio: 3.52
Engine RPM: 6500 Redline = 41.6970892440055 MPH (Up-Shift Engages 2nd Gear @ 3940 RPM)

2nd Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 3.615
2nd Gear Ratio: 2.043
Engine RPM: 6500 Redline = 71.84226830097863 MPH (Up-Shift Engages 3rd Gear @ 4650 RPM)

3rd Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 3.615
3rd Gear Ratio: 1.401
Engine RPM: 6500 Redline = 104.76356469585963 MPH (Up-Shift Engages 4th Gear @ 4845 RPM)

*4th Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 3.615
4th Gear Ratio: 1.000
Engine RPM: 6500 Redline = *146.77375413889936 MPH

**5th Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 3.615
5th Gear Ratio: 0.717
Engine RPM: 6500 Redline = **204.7053753680605 MPH

**6th Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 3.615
6th Gear Ratio: 0.586
Engine RPM: 6500 Redline = **250.46715723361663 MPH


6th Gear - 50% of Redline:
Engine RPM: 3250 = 125.23 MPH


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Below are ground speeds at 6,500 RPM engine redline for all 8 gears (2015) RWD - AA81E 8-Speed Automatic:
(Speed limiter is electronically governed at 142 MPH preventing max speed of ~170 MPH • **Engine will not reach redline in 6th, 7th or 8th gear)

1st Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 2.937
1st Gear Ratio: 4.596
Engine RPM: 6500 Redline = 37.66565457305995 MPH (Up-Shift Engages 2nd Gear @ 3855 RPM)

2nd Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 2.937
2nd Gear Ratio: 2.724
Engine RPM: 6500 Redline = 63.55042159243155 MPH (Up-Shift Engages 3rd Gear @ 4440 RPM)

3rd Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 2.937
3rd Gear Ratio: 1.863
Engine RPM: 6500 Redline = 92.92074525914309 MPH (Up-Shift Engages 4th Gear @ 5110 RPM)

4th Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 2.937
4th Gear Ratio: 1.464
Engine RPM: 6500 Redline = 118.24545656952431 MPH (Up-Shift Engages 5th Gear @ 5465 RPM)

5th Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 2.937
5th Gear Ratio: 1.231
Engine RPM: 6500 Redline = 140.62660310136764 MPH (Up-Shift Engages 6th Gear @ 5280 RPM)

**6th Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 2.937
6th Gear Ratio: 1.00
Engine RPM: 6500 Redline = **173.11134841778357 MPH

**7th Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 2.937
7th Gear Ratio: 0.824
Engine RPM: 6500 Redline = **210.0865878856597 MPH

**8th Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 2.937
8th Gear Ratio: 0.685
Engine RPM: 6500 Redline = **252.717296960268 MPH


8th Gear - 50% of Redline:
Engine RPM: 3250 = 126.35 MPH

igetit14is

So i guess you missed the part that I'm in a 2014 IS350F ,, oh and that car runs a stagger 225/40/18 and 255/35/18, and those tires are almost an inch shorter than the tires you calculated.
so if you're going to correct me, correct me correctly, and please do, I'm interested in the spec for the sizes my car runs

ChronoR

Smaller tires just mean a slightly lower theoretical top speed though? It doesn't seem like it could drop from 210MPH to 160MPH.

bclexus

Yes, I missed the part that you are in a 2014 IS350F - because I replied to your post (which I quoted) before you posted your 'clarification' (noted directly above in red). Maybe you should have edited your original post...

bclexus

The IS350 8-speed transmission gear ratios are the same as the GS 350, but the final (differential) gear is shorter and his rear tire circumference is a bit less. As a matter of fact, either his speedometer was off or his tachometer was off, or both were off - because 6,000 RPMs in 7th gear with his final gear and his rear tire size does not compute to a speed of 161 MPH.

Ethanol

146 MPH / 234 km/h in my case (2015/16 IS200t F-Sport)
It seems the top speed is limited electronically.
This is the very end of the 6th gear, and the car didn't accelerate further in 7th.
The engine has enough torque to reach this speed in 8th gear when accelerating from e.g. 70MPH.