3.55 rear pumpkin differences?

[JoeCee]

Can some please tell me for a street cruiser only what one what be better as I’m upgrading my 10 speed from 3.15. Not sure about trac-loc vs Torsten?

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[Rob00GT]

A basic limited slip diff with clutch pack (like traction lock) will work fine for a cruiser. No need to spend the extra funds on Torsen or other mechanical locking diff.

 

[Oakley]

the only way you'll notice a torsen diff is if you actually drive the car in a way that is more than just cruising... and its noticeable if you do that.

 

[rickytan05]

3.55= gas guzzler
Sometimes I wish I had 3.15 gear differential but I love my top end speed

 

[CharlieB714]

Can some please tell me for a street cruiser only what one what be better as I’m upgrading my 10 speed from 3.15. Not sure about trac-loc vs Torsten?

I AM HAVING TO DO SOME MAINTENANCE ON MY REAR END DIFF. I HAVE A 10R80 AUTOMATIC TRANS AND I AM RUNNING 20" WHEELS ALL AROUND 20X9 FRONT AND 20X11 IN THE REAR. WOULD LIKE TO BE ABLE TO CRUISE AND BE FAST AS WELL WHAT CAN YOU TELL ME ABOUT YOUR UPGRADE?

 

[sdskinner73]

3.55= gas guzzler
Sometimes I wish I had 3.15 gear differential but I love my top end speed

That’s completely false. My first GT was a 2019 3.15. I drove more then, sat around 23mpg. 2018 3.55 now, and sitting at 24. Both highway miles almost exclusively. The 3.15 feels faster up top, the 3.55 is quicker down low. They’re both good options. Unless you want boost, I would go 3.15 in that case.

 

[rickytan05]

 

[sdskinner73]

I’d like to see consistent videos of this. I don’t have personal data to back it up, which is why I said “feels”. My 0-60 per the dash is faster in the 3.55, but that’s fully expected. It’s just not the gas guzzler. I expected the same, but real life has shown different.

 

[TonyT930]

Can some please tell me for a street cruiser only what one what be better as I’m upgrading my 10 speed from 3.15. Not sure about trac-loc vs Torsten?

I have the 3:15 gears and would stay with them. Plus, if you supercharge or turbo later, you will be glad you stayed with the 3:15

 

[Superspirit]

I have 4.09's and still get 25 on the highway. MT82D4 in my 19gt

 

[Bob Lob Law]

That seems about right to me. When I was shopping for my car I drove SEVERAL 3.15-3.55 cars back to back to back. After doing so I was dead set on a 3.55 car.

 

[sdskinner73]

That seems about right to me. When I was shopping for my car I drove SEVERAL 3.15-3.55 cars back to back to back. After doing so I was dead set on a 3.55 car.

When looking on YouTube, this is the only video showing 3.55 pulling better. From what the comments seem to gather, the 3.15 is a base model and the 3.55 was not. So this comparison isn’t fair. Drag mode 3.55 should be faster.

 

[Snakebyte]

That’s completely false. My first GT was a 2019 3.15. I drove more then, sat around 23mpg. 2018 3.55 now, and sitting at 24. Both highway miles almost exclusively. The 3.15 feels faster up top, the 3.55 is quicker down low. They’re both good options. Unless you want boost, I would go 3.15 in that case.

Mathematically I can't resolve the increased fuel mileage of a specific car after a 3:15 to 3.55 diff change alone (IF exact driving behaviors, fuel blends (incl summer vs winter, ethanol content, etc), weather, and other potential variables stay the same.) "Quicker down low" is a great seat-of-the-pants comparison.

I'm thinking, however, the post may be summarizing fuel mileage comparisons between 2 different GT's with the two different gear ratios. In that case, it is ABSOLUTELY POSSIBLE, between two different GT's, one with 3.15 and the other with 3.55, as there are numerous additional variables thrown in the mix. (Tires, temps, tunes, engine-to-engine variability, etc.)

All that said, I have considered a 3.15 to 3.55 change, regardless of fuel mileage offsets. I love the seat-of-the-pants dyno results.

 

[sdskinner73]

Mathematically I can't resolve the increased fuel mileage of a specific car after a 3:15 to 3.55 diff change alone (IF exact driving behaviors, fuel blends (incl summer vs winter, ethanol content, etc), weather, and other potential variables stay the same.) "Quicker down low" is a great seat-of-the-pants comparison.

I'm thinking, however, the post may be summarizing fuel mileage comparisons between 2 different GT's with the two different gear ratios. In that case, it is ABSOLUTELY POSSIBLE, between two different GT's, one with 3.15 and the other with 3.55, as there are numerous additional variables thrown in the mix. (Tires, temps, tunes, engine-to-engine variability, etc.)

All that said, I have considered a 3.15 to 3.55 change, regardless of fuel mileage offsets. I love the seat-of-the-pants dyno results.

My 3.15 never got below a 5 on the 0-60 per the dash. My current best with the 3.55 is 4.7. Tire size are different, but the 3.15 had 20” nittos. Only all season 19s on my 3.55 as of yet.

 

[Superspirit]

When I first bought my gt it had 3.55's it got 27mpg hwy. I swapped in the 4.09's and taking the exact same trip, same car, same cruise setting and I now get 25. I don't know how you could dispute that comparison. Sometimes the lower gearing increases fuel mileage by reducing the load on the engine. It doesn't have to labor as hard with the lower gearing. I've seen 3.55' get better mileage than 3.15's.

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