87 Diablo Tune in 6.2

[reardiff]

I just got my Diablo tuner and like a kid on Christmas can't wait to play with it.  My main reason for buying was to turn off AFM and to adjust for tire size however thought I might as well install one of the canned tunes it has.   What I'm not understanding is why there is an 87 tune option when the 6.2 already uses premium (91/93).  What's the advantage in going with 87 tune in the 6.2? The Diablo website says the 87 tune has +13 HP and +18 TQ for the 6.2?  So by going down to 87 your actually increasing the HP and TQ numbers?  

 

Also, anyone have a list of parameters these canned tunes are set for?  I've searched high and low and can't seem to find anything that tells you what settings or parameters these are set for?

 

 

[Ryno12]

I used 87 in my 6.2 all the time & never had issues. Never noticed a difference when I ran premium other than the cost so I stuck with 87. I eventually bought a tuner and out of curiosity, put the 93 tune in and ran premium fuel. I did that for a few tanks and honestly wasn’t impressed in the slightest. I was expecting a noticeable gain but it actually ran worse. Switched to 87 tune & went back to 87 fuel and it ran noticeably better, even when pulling our 8600# TT. I got better mileage with 87 & it felt like it ran better & had more power.

Perhaps it’s an anomaly but my 6.2 preferred 87.

[CamGTP]

I don't think I've ever pulled a tune from a 2014+ truck that used that tuner before. The previous trucks wouldn't really change a whole lot.

 

Mainly just minor timing changes and changed to commanded fueling during power enrichment. Some may lessen the nannies like torque mngt and they will quicken the response into PE so there is less delay.

 

Having tuned and helped tune several of these trucks, going down in a fuels octane allowed for more spark retard. Eventually at a certain point it would just run off the lower octane timing curve within the calibration.

 

Running 87 octane or 93 octane would not make a difference at cruising speeds. The direct injection is another huge reason why, the cooling effect inside the combustion chamber with DI engines is very good.

 

These computers can also not read octane, they can only read alcohol content in the fuel if the Flex Fuel feature is working. The engineers have just been really smart to allow the calibrations to work with any fuel you put in it. All out power would not be achievable with 87 octane and that's been proven a million times over.

 

To sum this all up, I doubt you'd ever get a true break down of what is actually changed unless someone was able to read the file with a tuner like HP Tuners to see what is different from stock. Why they offer a 87 tune is something I wonder about but whatever. I don't see a reason change the fuel you are running though, keep with premium if you ask me.

[KARNUT]

Every tune I’ve ever used said use premium fuel with the performance tune. They will give the option for using regular fuel with a tune. That’s on vehicles that already use regular fuel. They may quicken throttle response firm up shifts. That will make it feel more responsive. A 87 gas tune on a 6.2 can only be pulling performance.


Sent from my iPhone using Tapatalk

[reardiff]

1 hour ago, KARNUT said:

 87 gas tune on a 6.2 can only be pulling performance

That's what I was thinking, but on their website it says 13 HP and 18 TQ, which to me don't add up, how can you get those kind of gains by taking a stock 6.2 and putting in an 87 tune?  I will likely email them this same question and maybe run the 87 tune and keep using 93 gas for a while and see if I notice any difference. 

 

Here's what it says on their website:

I'm a little hesitant on running the 91/93 tune because what happens if you get a bad tank of gas that may have less than 91?  Stock it would just pull timing to adjust, but with the tune would it still adjust or just start detonating.  Maybe I'm way over thinking this, and at some point after warranty is past I may go the custom tune route which i know is much better all the way around, but for now I need something I can return to stock when it goes in for service. 

 

Anyways thanks for the comments, really enjoy this site and the amount of knowledge and experience on here. 

 

[KARNUT]

That's what I was thinking, but on their website it says 13 HP and 18 TQ, which to me don't add up, how can you get those kind of gains by taking a stock 6.2 and putting in an 87 tune?  I will likely email them this same question and maybe run the 87 tune and keep using 93 gas for a while and see if I notice any difference. 
 
Here's what it says on their website:

I'm a little hesitant on running the 91/93 tune because what happens if you get a bad tank of gas that may have less than 91?  Stock it would just pull timing to adjust, but with the tune would it still adjust or just start detonating.  Maybe I'm way over thinking this, and at some point after warranty is past I may go the custom tune route which i know is much better all the way around, but for now I need something I can return to stock when it goes in for service. 
 
Anyways thanks for the comments, really enjoy this site and the amount of knowledge and experience on here. 
 

Some GM trucks will self tune for more HP and TQ with E-85. If there are tunes to add HP on the 6.2 and safety use req gas that be good to know. Keep us informed.


Sent from my iPhone using Tapatalk

[99SSCamaro]

I have a diablo tuner - only a 5.3 though, But have had it on my last 3 trucks. The way I understand it, the 87 octane tune doesn't necessarily mean you need to run 87, it's just a basic general tune - supposed to give a small increase in power and mileage, while decreasing the factory nannies. The diablo (93) tune is the performance tune, and requires 93 octane to get the most performance. I'd say load the 87 octane tune, and run whatever fuel you want. The computer will adjust regardless.

[reardiff]

26 minutes ago, 99SSCamaro said:

I have a diablo tuner - only a 5.3 though, But have had it on my last 3 trucks. The way I understand it, the 87 octane tune doesn't necessarily mean you need to run 87, it's just a basic general tune - supposed to give a small increase in power and mileage, while decreasing the factory nannies. The diablo (93) tune is the performance tune, and requires 93 octane to get the most performance. I'd say load the 87 octane tune, and run whatever fuel you want. The computer will adjust regardless.

 

For a 5.3 I agree, since it comes stock to run on 87, but the 6.2 comes stock tuned to run on 91/93.  If it comes form the factory to run on 91/93 how can going to 87 make any kind of increase in power or performance, other than like CamGTP mentioned with removing some of the nannies like torque management, shift points/firmness, etc.. 

 

At the end of the day I know we're not talking crazy numbers here especially when comparing one tune to the other and will likely result in minimal seat of the pants improvement, but I just don't want to go backwards by putting in an 87 tune in an engine that's designed to run on 91/93 when it rolled off the lot. 

[BlackBearPerf]

Just wanted to add our two cents, the tuner won't even provide an tune for anything less than 91+ for the 6.2, that fuel is required for both optimal economy and best power.  
87 octane and, to a lesser extent, 89 octane both cause persistent, detrimental pinging with that engine.

[reardiff]

Interesting... And makes complete sense and along the lines of what I was thinking when I started this topic.  I have yet to plug it in (arriving today) to see what the options are but based off their own website they show an 87 tune option for the 6.2 and claiming +13 HP and 18 TQ.   If it's available when I plug it in I may try it but wouldn't run anything less than 93 anyways, always have.

 

The whole concept of an 87 tune in 6.2 just doesn't gel right in my mind. Perhaps it's all smoke and mirrors and marketing ploy, which wouldn't be unheard of.  And I just wanted the darn thing to turn off AMF and adjust tire size.  See what curiosity, a few hundred bucks and a forum like this gets you...   

[Ryno12]

87 octane and, to a lesser extent, 89 octane both cause persistent, detrimental pinging with that engine.

I know you’re the SME here but my experience with 87 in my 6.2 has been great. Where I’m located, we only have 87, 89, & 91. When I used the 91 (with or without a tune), it ran worse. There was hesitation & the truck felt down on power. Gas mileage was also worse.

87 ran great & I never experienced any pinging.

Honest question, what would cause this? Everything I’ve read says the 6.2’s need premium fuel, however my experience says otherwise. Could it just old or bad fuel? I don’t see many people using premium fuel in area so perhaps it’s just old?!

[BlackBearPerf]

40 minutes ago, Ryno12 said:

I know you’re the SME here but my experience with 87 in my 6.2 has been great. Where I’m located, we only have 87, 89, & 91. When I used the 91 (with or without a tune), it ran worse. There was hesitation & the truck felt down on power. Gas mileage was also worse.

87 ran great & I never experienced any pinging.

Honest question, what would cause this? Everything I’ve read says the 6.2’s need premium fuel, however my experience says otherwise. Could it just old or bad fuel? I don’t see many people using premium fuel in area so perhaps it’s just old?!

It definitely could have been the fuel quality. Running 87 you would still have pinging going on every mile, even if it is not audible. 

[L86 All Terrain]

16 hours ago, Ryno12 said:

I know you’re the SME here but my experience with 87 in my 6.2 has been great. Where I’m located, we only have 87, 89, & 91. When I used the 91 (with or without a tune), it ran worse. There was hesitation & the truck felt down on power. Gas mileage was also worse.

87 ran great & I never experienced any pinging.

Honest question, what would cause this? Everything I’ve read says the 6.2’s need premium fuel, however my experience says otherwise. Could it just old or bad fuel? I don’t see many people using premium fuel in area so perhaps it’s just old?!

 I don't hear my snowmobile pinging either at 8,000rpm on 91 octane so I assumed it was not occurring, my melted pistons said otherwise. Now I mix 100LL and premium. I have run regular in my 6.2L before maybe 4-5 times but for the extra $10 I just fill it with the recommended gas. You wont hurt the engine running regular, it can take it but it is not recommended for longevity reasons. I find it highly doubtful that your truck runs worse on 91 than it does 87 and lost economy, I would say that is all attributed to driving habits. It also depends where you get your gas, some stations in Canada only blend 10% ethanol, while other stations are as high as 15-20%. Octane ratings may be similar between the two fuels, but premium is not blended with ethanol. 

[Ryno12]

I find it highly doubtful that your truck runs worse on 91 than it does 87 and lost economy, I would say that is all attributed to driving habits. It also depends where you get your gas, some stations in Canada only blend 10% ethanol, while other stations are as high as 15-20%. Octane ratings may be similar between the two fuels, but premium is not blended with ethanol. 

Obviously it’s nothing that I can prove but it’s also nothing that I’d lie about, just an experience that I had. I can say with certainty that it had absolutely nothing to do with “my driving habits”.
There was a noticeable difference (for the worse) when I ran 91 vs 87. The only thing that would make any sense is perhaps old/poor gas.

Anyway, I no longer have the truck so it’s water over the dam.

[TJay74]

On 11/27/2019 at 4:44 PM, Ryno12 said:

I know you’re the SME here but my experience with 87 in my 6.2 has been great. Where I’m located, we only have 87, 89, & 91. When I used the 91 (with or without a tune), it ran worse. There was hesitation & the truck felt down on power. Gas mileage was also worse.

87 ran great & I never experienced any pinging.

Honest question, what would cause this? Everything I’ve read says the 6.2’s need premium fuel, however my experience says otherwise. Could it just old or bad fuel? I don’t see many people using premium fuel in area so perhaps it’s just old?!

 

Let me reaffirm what Ryan said, you can be running on borrowed time putting 87 octane in the 6.2. They will show detonation running 91 during the warmer summer months bone stock. GM has changed their warranty stand point as well in that regards. If the vehicle says it needs premium fuel and you run 87/89 and cause engine damage GM can and will deny coverage for the damage due to the owner not running the correct octane fuel.

This isnt a Gen3 Chevy small block here, it is really hard to hear detonation in the Gen5 engines due to them being all aluminium in construction it dampens the sounds that detonation makes. I have logged several K2xx trucks with HP Tuners and as Ryan said, the 5.3 and 6.2 trucks are bad about detonation in stock form on all grades of gas, the issue worsens when the warmer weather is around and the IAT's are up higher.

The trucks have 2 static timing maps, one is the high octane map and one is the low octane map. When the ECM sees detonation it drops down into the low octane map to try and reduce the detonation and other that some modifier tables that modify the final timing based on intake air temps, oil temps and coolant temps that is the only defense it has to limit the damage that detonation causes to the engine. After the detonation stops and the last event decay's out the ECM will then move back into the high octane map until the next detonation event kicks it back down again.

With that info, you can add 10% of your tank size in E85 and will greatly help with detonation, especially if you add it along with 91/93 octane fuel. Before I went full E85 I ran as much as 15% with zero issues and the truck ran great with way less knock events. The base fueling tables are already setup to allow for E10 fuel to be used. E85 is a huge improvement, but that will require tuning to get it to work and possibly adding the ethanol sensor to the truck.

Thats my take on it, it's your vehicle so do as you want. I have owned 2 - 6.2 K2xx trucks now and have always ran them on 91 at the minimum.