What RPM are you at, in 5th Gear @ 60 MPH?

[red golf tdi]

What RPM are you at, in 5th Gear?

I'm researching the taller 5th gears for my ALH and trying to determine what I need. There's a lot of information out there and read in depth on the club here. I do half my 100 mile per day commute at 75 MPH, and half at 60 MPH. I know the recommendations, but would like real world RPM numbers from folks since I know when my engine lugs with all my mods. (different lug point than no mods).

In order for me to make my decision, I need to know at what RPM are you turning @ 60 MPH in 5th gear. I understand VW speedometers are off, and different tire brands, but let's just do what the needle points to for all practical purposes of this request.

I'll start off:

.756 - Factory stock gear @ 60 MPH I'm turning approx. 2050 RPMs

.717 @ 60 MPH I'm turning xxxx RPMs

.681 @ 60 MPH I'm turning xxxx RPMs

.658 @ 60 MPH I'm turning xxxx RPMs
​

Just copy and paste and fill in the blank! Thanks!

 

[supton]

My PD is turning about 2k at 60mph. I do enough highway that a taller 5th would work ok, I might be happy with the results at 60mph on the backroads too--it is a torquey motor afterall. If 5th gear dies on my trans, it might be worth a swap. Then again, it responds pretty good when I get on it--a taller gear is going to remove some of that snap.

What is your goal? Better mpg's, or just swapping gears for fun?

 

[Joester]

.756 - Factory stock gear @ 60 MPH I'm turning approx. 2050 RPMs

.717 @ 60 MPH I'm turning 1944 RPMs

.681 @ 60 MPH I'm turning 1847 RPMs

.658 @ 60 MPH I'm turning 1784 RPMs


Source: Math

Bonus: these numbers will be specific to your car's tires too!


I could see real world examples being needed for sayyy MPG or 0-60 times, but when its something as specific and set as gear ratios, and thats the ONLY thing that's changing, the math might as well be real world.

 

[red golf tdi]

Thanks but this wasn't my intent....math aside, I want to know what people are actually seeing as I've seen different percentages of these gears posted on the web. Real world is validation/ confirmation of the math.

 

[BobnOH]

The math is correct, other factors will be particular to a given car, transmission slip (should be 0), tire size.
If you think about it, the crankshaft has to turn x rotations to turn the drive shaft y revolutions.

 

[Joester]

If your engine's crankshaft is turning XXXX RPM with a .XXX 5th gear, then your axles are going to be spinning at a corresponding RPM. Period. That's all math and wont differ car-to-car at all. Not even by 1 RPM.

From there, your tires' rev/mi determines how fast you're going down the highway for that given crankshaft RPM.

So what I'm saying is that just using math with be the absolute most accurate way to determine what your RPMs will be after a 5th gear swap.

Any other "real world" numbers that you're hearing are because people either
-have different sized tires
-arent reading the speedo like you are
-arent reading the tach like you are
-combination of the above 3


I understand that math isn't your intent, but bottom line is that math will be the most accurate post-5th-gear-swap RPM estimation for you and your specific setup because it will give you the RPMs you will see as you read them off your tach, at the speed that you are reading off your own speedometer, with your own tires' rev/mi.

 

[Enabled]

.681 @ 60 MPH I'm turning ~1825 RPMs

.681 @ 83 MPH I'm turning ~2600 RPMs

.681 @ 97 MPH I'm turning ~3000 RPMs