Premium fuel =less mpg.

[Mister H12]

The tune will help with performance and usually mpg, though if you want better mpg.. you shouldn't have bought a yukon..

The 6.0 will need a new tune, but it'll be worth it in the time to just tune your 4.8.

Octane boosters are good, but you shouldn't expect a great increase in mpg, more than likely you just happened to drive differently that week and got better mpg.

Not trying to hurt peoples feelings but again.. if you're worried about mpg.. buy a compact :]

 

[WeekendPlinker]

The tune will help with performance and usually mpg, though if you want better mpg.. you shouldn't have bought a yukon..

The 6.0 will need a new tune, but it'll be worth it in the time to just tune your 4.8.

Octane boosters are good, but you shouldn't expect a great increase in mpg, more than likely you just happened to drive differently that week and got better mpg.

Not trying to hurt peoples feelings but again.. if you're worried about mpg.. buy a compact :]

It was a non stop trip from ms to sc nearly 700 miles all on cruise control at 70mph. Back to back tanks of fuel...

At home, around town I consistently get 14.5 mpg my driving habits are the same every day. Nothing differs but the weather.

Mpg isn't a huge concern for me as I knew the truck wouldn't get that great of mpg when I bought it. Just trying to figure out why the differences... And what could be done to make it better. If an additive can boost mpg that much, there's gotta be something else out there that works as well.

 

[JennaBear]

Were hills involved?

 

[WeekendPlinker]

Were hills involved?

All flat

 

[FrankU]

Got a BB tune for premium , run's just as strong and gets better fuel mileage on regular. Go figure.
I'm very happy with the BB tune !

 

[ccapehartusarmyINF.(ret)]

premium or 93 octane doesnt mean its better quality fuel or that its going to burn cleaner.
it actually relates to just how much a fuel can be compressed before igniting. The higher the number, the less likely it is to ignite under pressure. or knock resistance (knock is when the fuel combusts before the spark)
all the GM engines (non-flex fuel) for trucks and suburbans are generally a 9.5:1 and 87 octane is a high enough knock resitance any higher is pointless
so basically superunleaded engines need super and regular unleaded motors dont
now as far as a tune is concered its a little confusing to me and maybe someone from blackbear can answer this, what does tuning a Naturally asp 9.5:1 comp ratio 87 oct. motor to run 91 octane accomplish

 

[JennaBear]

More power. Commission isn't the only factor in respect to octane.

It isn't unheard of for this year vehicle to see better MPGs with 87.

 

[Wake]

With regular unleaded I average 14.5-15 mpg city.

Have filled up with premium twice now and I'm only averaging 11.5-12.5 mpg.

Isn't this bass ackwards??

Nope, you engine was designed to run 87 octane gas, the lowest octane you can run without knock will yield the best efficiency.

All of my vehicles are labeled, 'premium required'. In all but my older Corvette I run mostly 89 octane because it gets the best fuel economy for my driving style. Even my supercharged STS-V and the turbocharged Saturn Sky Redline I had prior to the STS get better fuel economy on 89 in steady state driving conditions (normal throttle). All my vehicles except the Vette and the Escalade lose about 2mpg on 93 octane. The Escalade seems to do better on 89 but not a lot of difference in economy over 93. The Vette is older engine control technology, with a 10.8:1 compression ratio on top of that it pings even on the 91 octane I was limited to when I lived in CA.

Now if you're driving hard and your vehicle requires premium fuel then you will notice a difference. My STS loses some at the top end when I'm not running 93. My Sky also behaved the same way. I usually only put 93 in when I'm feeling a bit spunky and want to flog the car a little bit.

---------- Post added at 02:41 AM ---------- Previous post was at 02:32 AM ----------

...now as far as a tune is concered its a little confusing to me and maybe someone from blackbear can answer this, what does tuning a Naturally asp 9.5:1 comp ratio 87 oct. motor to run 91 octane accomplish

I think tuning is simply a matter of recalibrating the timing advance and leaning out the fuel mixture a little bit. The manufacturers all run a bit conservative, richer fuel mixture and less timing advance for safety. As far as I know engine wise, those two things are the only items you can modify outside of physical changes like cams, headers, etc that will change your engine's behavior.

You can always go more aggressive in tuning, but nothing comes for free. I'm going to have to say that it will probably cost you in reliability later down the road, assuming you drive it harder because you have more power. That's something the manufacturer isn't going to give you if it will hurt their reliability and bottom line in warranty repairs.

 

[01ssreda4]

For our trucks the timing is made for 87 octane, running 91 will only cause the engine to run rich resulting in lower mileage and more fuel burnt.

If you truck engine is set for 87 down gasoline, so you do not put 92 or high, if you truck has a yellow gas cap that mean you ignition timing is way down , when you use 92 plus gas is not going to work right. you have to tune the engine and you see the difference.

These two responses stick out in my head. You two sound like soccer moms repeating some crap you heard at a PTA meeting. Seriously, pass on good correct information so readers will become smarter. Its obvious you two have NEVER seen the inside of a tune, and if that's the case why don't you learn before you talk?

I think tuning is simply a matter of recalibrating the timing advance and leaning out the fuel mixture a little bit. The manufacturers all run a bit conservative, richer fuel mixture and less timing advance for safety. As far as I know engine wise, those two things are the only items you can modify outside of physical changes like cams, headers, etc that will change your engine's behavior.

A couple of the things I change right away on a stock motor are: Stoich number to match today's e10 fuels, timing advance, power enrichment amount (leaner), rpm it activates (sooner), and how quick PE ramps in (faster). Couple this with some 91 octane, cold air intake, and maybe a catback or muffler and it will really wake a stock engine up!

 

[Wake]

A couple of the things I change right away on a stock motor are: Stoich number to match today's e10 fuels, timing advance, power enrichment amount (leaner), rpm it activates (sooner), and how quick PE ramps in (faster). Couple this with some 91 octane, cold air intake, and maybe a catback or muffler and it will really wake a stock engine up!

Ah, I didn't even consider the E10 blends of today's gasoline. Yeah, most of us have vehicles that were designed before the blends became the norm.

With today's advanced engines and controls I'm kinda interested again in the tuning aspect. Especially on something like the NNBS Escalade with the 6.2L and VVT. I've got the 4.4L VVT supercharged LC3 in my V and it seems like those guys are getting quite a bit out of them with the tunes nowadays. Still weighing the options of tuning versus my lifetime powertrain warranty.