2018 GT Auto with 3.15. How much does a Tune Help?

[Timeless]

So, I'm testing out a 2018 GT Premium Convertible for the weekend to see if I want to buy.


It is right off the truck so I am being reasonable with it. The dealership was nice enough to order this with the thought I'd get it. One item that did not get put on the order was 3.55 rear end.


So fast forward to now and I feel a bit underwhelmed by the initial acceleration. I'm not flooring it obviously but it seems like it takes a good bit to get this thing moving in a matter that is pleasing.


Keep in mind I am coming from the RS which is lighter, turbo charged, and a manual transmission...so it might just be me.


So after the initial break in my plan was to do a dry filter and flex tune.


For those that have done this, did it help immensely?


My other option is to let this go and let them get a 2019 in with the correct rear end. My problem with that is that Royal Crimson is gone for 2019 and would most likely go with Ruby Red.

Thanks!

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[GreenS550]

It depends on your ultimate objective. Tunes, especially on automatics, have really been a mod that give much better throttle response. A goodly number of fast stock GTs have the 3.15 gear in them. Speaking from experience, if you keep it NA with minor mods, the 3.55, which is the gear I have, is the way to go. If you SC it with a PD blower, like I did, the 3.55 gear is almost too much gear unless you want to drive with drag radials or wider tires. I would not buy the stick without the 3.73 gear, though. 6 speeds vs 10 in the auto needs more mechanical advantage in my opinion, especially with Ford changing the ratios to 1:1 in 4th vs 5th in 2017.

 

[brucelinc]

In normal drive mode, the throttle tip-in is pretty relaxed with the A10. The first time I drove one, I was also underwhelmed. My previous Mustang was a manual and the A10 just seemed a bit lethargic in comparison.

However, they wake up considerably in the other drive modes and throttle tip-in is more aggressive. Additionally, they feel much better after fully broken in.

 

[GTBOB]

When you test drove the '18, did you try any driving modes too? Sport+ mode via the toggle switch (if equipped) really helps. The throttle response is sharper and holds each gear a little longer.

I have a Royal Crimson '18 GT with Black Accent Pkg., Active exhaust, 301a Pkg with Nav, 3.15, auto. I have a Lund E85 tune and JLT Intake. It has no problem accelerating.

I came from a manual '15 GT with 3.55 that ran 11.51 at 120mph (Lund tune, GT350 stuff....). I have a good comparison of what acceleration should feel like between the too. Once I get a decent tire on the '18, it will have no problem beating my old '15.

 

[Labradog]

So, I'm testing out a 2018 GT Premium Convertible

That's also the fattest pig in the barn.

 

[LETHAL]

I drove a A10 3.15 18 GT Premium before choosing mine with 3.55s.

Yes there is a difference, but I would not say it is earth shattering. The Premium also had some weight on my base with 301A option.

I would expect that A good tune would make the car feel like night and day.


Off topic

GTBOB... OMG man... BEAUTIFUL!

 

[Lonmon]

I felt the same way but just driving in S instead of D makes the difference. The tune of course helps too. I drive in D going back and forth to work for fuel mileage and then in S when I want to have fun. Way more responsive and ready for acceleration. I still go back and forth about whether I made the right decision about sticking with 3:15's. I'm sure I will be happy I did if I go boost later.

 

[10r80]

Below are some videos of my 10r80 18 w/ 3.15's with a flex fuel tune - took a wrong turn both times and ended up in Mexico.

[ame]

[ame]

 

[Timeless]

It depends on your ultimate objective. Tunes, especially on automatics, have really been a mod that give much better throttle response. A goodly number of fast stock GTs have the 3.15 gear in them. Speaking from experience, if you keep it NA with minor mods, the 3.55, which is the gear I have, is the way to go. If you SC it with a PD blower, like I did, the 3.55 gear is almost too much gear unless you want to drive with drag radials or wider tires. I would not buy the stick without the 3.73 gear, though. 6 speeds vs 10 in the auto needs more mechanical advantage in my opinion, especially with Ford changing the ratios to 1:1 in 4th vs 5th in 2017.

I do not plan on any forced induction.

In normal drive mode, the throttle tip-in is pretty relaxed with the A10. The first time I drove one, I was also underwhelmed. My previous Mustang was a manual and the A10 just seemed a bit lethargic in comparison.

However, they wake up considerably in the other drive modes and throttle tip-in is more aggressive. Additionally, they feel much better after fully broken in.

I basically drove only in sport mode and with the shifter in Sport. I wanted to play with the paddles and enjoy the downshifts coming to stops.

When you test drove the '18, did you try any driving modes too? Sport+ mode via the toggle switch (if equipped) really helps. The throttle response is sharper and holds each gear a little longer.

I have a Royal Crimson '18 GT with Black Accent Pkg., Active exhaust, 301a Pkg with Nav, 3.15, auto. I have a Lund E85 tune and JLT Intake. It has no problem accelerating.

I came from a manual '15 GT with 3.55 that ran 11.51 at 120mph (Lund tune, GT350 stuff....). I have a good comparison of what acceleration should feel like between the too. Once I get a decent tire on the '18, it will have no problem beating my old '15.

Played with all the modes...settled on sport mode and shifter in sport.

That's also the fattest pig in the barn.

Yep, it definitely feels it too.

I felt the same way but just driving in S instead of D makes the difference. The tune of course helps too. I drive in D going back and forth to work for fuel mileage and then in S when I want to have fun. Way more responsive and ready for acceleration. I still go back and forth about whether I made the right decision about sticking with 3:15's. I'm sure I will be happy I did if I go boost later.

Good to hear a tune wakes it up.


So basically at this point I've decided against the convertible.


For the price of the vert, I can do the PP1 and have a much tighter sportier feeling car. Might even do Magneride and the B&O upgrade also.


It would be a 2019 and in Ruby Red.


Thanks for all the replies guys.

 

[Labradog]

That's what I'd do. Love Ruby Red (second best color to Guard :cheers

 

[Timeless]

So, the decision has been made to order a 2019 as no 2018s are around that fit my specs.

My thoughts are the following specs:

GT premium coupe with 400a
Ruby Red
Ceramic Leather Interior
10 speed auto
Performance pack 1
19" Luster Nickle Painted Forged Aluminum Wheels wheels (option 647)
B&O Pro (Former Shaker Pro)
Active exhaust
Magneride (not 100% on this)

I even thought about going 301a but it looks like you miss out on a lot of items (home link, heated/cooled seats, option to do B&O).

I should expect this version to be night and day different than the convertible correct in respect to the boat like feel?

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