2015 Suburban LTZ - BB tune-worthy?

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formula271

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Would my 2015 Suburban 5.3 benefit from a tune? It is an LTZ with the Max Trailering Package 3.42 gears.

Currently have ~35,000 miles. My only "performance" goodies are a Range AFM disabler and an almost exclusive use of premium fuel. Normally, I'd be suspicious of the benefit of running premium fuel in a vehicle that recommends 87....but there's gotta be something positive going on with the 93. The throttle response and feeling of more immediate torque, even at lower RPM's, is meaningful. When I am a bit more aggressive with the throttle, I'd swear the 93 yields stronger acceleration more effortlessly, and seems even to produce a bit more pleasant exhaust note.

The transmission tuning is frustrating, to say the least. Small increases in throttle seem to illicit upshifts at the most inopportune times. In general, the eagerness to get into the highest gear possible seems crazy. More recently, I drove a 2017 Tahoe LT with the 5.3, same 20" wheels/tires, and 6A...it had the 3.08 gears. Not sure what changes Chevy has made since 2015, but even this 2017 seemed infinitely more drivable. I know others still complain of 2017 issues, but the throttle response was worlds better than my 2015. I asked the dealership if an "update" was available to my 2015 that might make it more like the 2017....they looked at me like I was crazy.

I'm not a fan of just using the "trailering mode"...I think this yields unnecessary harshness for normal driving.

So, would a tune remedy my transmission shifting woes? From an engine performance standpoint, could I expect any HP/torque benefit? Mostly, I'm interested in increased drivability at light to moderate throttle, but it would be fun to know, too, that there is some benefit with a tune when I step on it.
 

swathdiver

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Would my 2015 Suburban 5.3 benefit from a tune?

Normally, I'd be suspicious of the benefit of running premium fuel in a vehicle that recommends 87....but there's gotta be something positive going on with the 93.

Absolutely, especially the transmission. Properly tuned, the transmission makes the truck drive completely different and that of course is better.

As for the fuel, you're experiencing what many of us have known for generations. Higher octane fuels provide all kinds of benefits and actually costs less to run due to their increased efficiency and long term affects on the fuel system. Keep at it and tell everyone about your experiences so that they too may benefit.
 
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08HoeCD

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In all seriousness, BBP will take your factory shift schedule and throttle response profile to an entirely different experience.

Run, don’t walk, to them.
 
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formula271

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is it reasonable to expect no adverse effects from a BB tune? I would hate to trade my current frustrations with new issues.
 
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formula271

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Anyone with a current gen 5.3 with the same impressions regarding a tune on an otherwise stock vehicle?
 

Justin

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Would my 2015 Suburban 5.3 benefit from a tune? It is an LTZ with the Max Trailering Package 3.42 gears.

Currently have ~35,000 miles. My only "performance" goodies are a Range AFM disabler and an almost exclusive use of premium fuel. Normally, I'd be suspicious of the benefit of running premium fuel in a vehicle that recommends 87....but there's gotta be something positive going on with the 93. The throttle response and feeling of more immediate torque, even at lower RPM's, is meaningful. When I am a bit more aggressive with the throttle, I'd swear the 93 yields stronger acceleration more effortlessly, and seems even to produce a bit more pleasant exhaust note.

The transmission tuning is frustrating, to say the least. Small increases in throttle seem to illicit upshifts at the most inopportune times. In general, the eagerness to get into the highest gear possible seems crazy. More recently, I drove a 2017 Tahoe LT with the 5.3, same 20" wheels/tires, and 6A...it had the 3.08 gears. Not sure what changes Chevy has made since 2015, but even this 2017 seemed infinitely more drivable. I know others still complain of 2017 issues, but the throttle response was worlds better than my 2015. I asked the dealership if an "update" was available to my 2015 that might make it more like the 2017....they looked at me like I was crazy.

I'm not a fan of just using the "trailering mode"...I think this yields unnecessary harshness for normal driving.

So, would a tune remedy my transmission shifting woes? From an engine performance standpoint, could I expect any HP/torque benefit? Mostly, I'm interested in increased drivability at light to moderate throttle, but it would be fun to know, too, that there is some benefit with a tune when I step on it.

Jeff, it looks like we haven't gotten back to you here on this one, I hope you've had your questions answered here or on email.

I'll go ahead and respond to follow up though for the rest of the world. You are not crazy to think that you are benefitting from running premium on that engine. Even mid-grade will provide a substantial bump in both power and mileage on the 2015+ DI 5.3L engine. GM "recommends" 87 octane in documentation for an engine that is mechanically designed (compression ratio) for higher. They are doing their uninformed customers as well as their image a disservice by not recommending 89 or 91+ be run.

The 2016 and 2017 models have a better throttle mapping off-idle than the 2014 (truck) and 2015 models do. Our tune will result in quite a bit better on all applicable models.

The shift points are all the same though between the different model/years, only differentiated by gear ratio. Your complaint about the indecisive shifting is very common -- probably the most common complaint we encounter. If you were to provide no detail at all, our strategy would be to delay each upshift by the speed equivalent of a few hundred RPM as well as alter the downshift points to be a bit more accessible. There is no reason that you should reach full engine power at 45% throttle at low RPM, but not have a downshift occur until 70%. That is a recipe for a spongy gas pedal and lackluster response.

We'll be happy to answer any other questions that you may have.
 
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