NipRing Posted February 13, 2014 Author Report Share Posted February 13, 2014 Why does the the inside of the gas door say " Premium Fuel Only"? I'm pretty sure no one sells 87 as "Premium". Quote Link to comment Share on other sites More sharing options...
cb2big4u Posted February 13, 2014 Report Share Posted February 13, 2014 The manual for ALL ss and vmax trucks say pump 91+. I'll let someone else deal. LOL Sent using Tapatalk. Quote Link to comment Share on other sites More sharing options...
BLNAWAY Posted February 13, 2014 Report Share Posted February 13, 2014 Why does the the inside of the gas door say " Premium Fuel Only"? I'm pretty sure no one sells 87 as "Premium". The manual for ALL ss and vmax trucks say pump 91+. I'll let someone else deal. LOL Sent using Tapatalk. Quote Link to comment Share on other sites More sharing options...
Brentd Posted February 14, 2014 Report Share Posted February 14, 2014 Guess I need to read the manual lol. I do know that it never knocked or pinged once before I put a 93 tune on it and was running 87 in it. I found something on a google search just now that says 87 minimum required and 91 recommended. Pretty sure it just retards the timing on the stock tune and you lose a little oomph. Mine hasnt seen a drop of 87 since i tuned it over a year ago. Literally sat my wife down and lectured her for thirty minutes so she would be aware that she can never put 87 in it if she had to stop and get gas in it. Bought her a maxima that says 91 on the fuel cap so now it is just habit for her if she has to fuel up the truck. Quote Link to comment Share on other sites More sharing options...
coal miner Posted February 14, 2014 Report Share Posted February 14, 2014 the map retards the timing i believe. so it takes care of the knock. yeah but you would just kill power and have crapy mpg I think. I've never tired it tho so I really don't know. Quote Link to comment Share on other sites More sharing options...
coal miner Posted February 14, 2014 Report Share Posted February 14, 2014 My truck say premium right on the gas cap. Every vehicle I've seen with a high compression motor is the same. These truck where tuned for premium form the factory. The lq4 and lq9 has different tunes form the factory. Same motor but the compression ratio and that why they recommend premium. Quote Link to comment Share on other sites More sharing options...
Brentd Posted February 14, 2014 Report Share Posted February 14, 2014 yeah but you would just kill power and have crapy mpg I think. I've never tired it tho so I really don't know. Yes, you lose some power with 87 on stock tune, but its a small loss (if the stock premium fuel tables were that aggressive nobody would rave about how well these trucks respond to a tune.) The only reason i can think of that would cause issues with these trucks running like crap on 87 is carbon buildup in the combustion chambers on higher mileage trucks that have not been taken care of causing a loss of cc's in the combustion chambers and effectively raising compression. A clean well taken care of 6.0 will run fine on 87, granted you wont get the small amount of timing advance that gm tunes into them, but if you are going to dump 93 into it, or whatever premium you have access to, why not just get it tuned and actually get performance gains. As for mpgs....i used to get 14 or so mpg average on 87, once i tuned it and started running 93 and some other bolt ons, my avg mpgs are in the high 10s to 11s. The shift points were raised, the throttle sensitivity was raised, as well as some other things that dont contribute well to getting good mpg. Quote Link to comment Share on other sites More sharing options...
cb2big4u Posted February 14, 2014 Report Share Posted February 14, 2014 yeah but you would just kill power and have crapy mpg I think. I've never tired it tho so I really don't know. Yes, you lose some power with 87 on stock tune, but its a small loss (if the stock premium fuel tables were that aggressive nobody would rave about how well these trucks respond to a tune.) The only reason i can think of that would cause issues with these trucks running like crap on 87 is carbon buildup in the combustion chambers on higher mileage trucks that have not been taken care of causing a loss of cc's in the combustion chambers and effectively raising compression. A clean well taken care of 6.0 will run fine on 87, granted you wont get the small amount of timing advance that gm tunes into them, but if you are going to dump 93 into it, or whatever premium you have access to, why not just get it tuned and actually get performance gains. As for mpgs....i used to get 14 or so mpg average on 87, once i tuned it and started running 93 and some other bolt ons, my avg mpgs are in the high 10s to 11s. The shift points were raised, the throttle sensitivity was raised, as well as some other things that dont contribute well to getting good mpg. K Sent using Tapatalk. Quote Link to comment Share on other sites More sharing options...
chpspecial Posted February 15, 2014 Report Share Posted February 15, 2014 There is more than just some bit of power between the low octane and high octane timing tables. On a gas motor the biggest difference in economy between the good gas mileage and bad is the right go pedal. A significant drop in economy usually is an indicator of a bad tune base tune Sent from my HTC6500LVW using Tapatalk Quote Link to comment Share on other sites More sharing options...
coal miner Posted February 16, 2014 Report Share Posted February 16, 2014 I think driving habits have a lot to do with mpg. When I'm light on the pedal and keep an eye on the instant mpg I can get 19-22 on the highway at 55. If I drive normal it's like around 15. Have to agree the factory tune isn't much. When I started modding my truck my easy on the pedal went with it. It's not worth running 87 in our truck IMO and you have to ask your self why would I run 87 in a SSS? These trucks aren't meant to be mpg friendly. If you want mpg buy a Prius. Quote Link to comment Share on other sites More sharing options...
2003_SuperSport Posted February 16, 2014 Report Share Posted February 16, 2014 (edited) I only get 9-11MPG 12MPG if I am easy and average of 10-11mpg ... All my fault though I just want to go fast when I step on the skinny pedal... Edited February 16, 2014 by 2003_SuperSport (see edit history) Quote Link to comment Share on other sites More sharing options...
Bouch252 Posted February 16, 2014 Report Share Posted February 16, 2014 Bottom line is that our trucks are not meant to run on 87 octane. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
zippy Posted February 27, 2014 Report Share Posted February 27, 2014 I'll add my thoughts on what I am reading here. First of all to say it runs fine on 87 has no point or bearing on the issue. Do you think putting in 87 is going to make it missfire or not start at all? The computer will pull the timing as it is designed, but if the computer is pulling timing to make it run on 87 that means it is seeing knock first to pull the timing. There is no reason with a 10:1 compression engine to run it on 87 octane. As for the two tune thing that is another pointless venture. Wide open in the tuning has absolultely nothing to do with idle or part throttle. If the tune is done correctly you'll get excellent milage as well as get the best performance it will give you on the fuel you run. A properly tuned wide open doesn't take more fuel to be right. The parts you chose to make the power however will have an effect on fuel milage as well as driving style. Other than that make sure your tuner dials the calibration in as close as possible and keeps your part throttle shift points down as well as TCC lock up points. Quote Link to comment Share on other sites More sharing options...
FastCrewCab Posted March 5, 2014 Report Share Posted March 5, 2014 When my truck was stock it got over 40 more miles per tank full running Premium than it did running Mid grade. So I ran premium all the time, if you figure it out in Pennies per mile it's actually cheaper to run premium. Now that I've Modified the Hell out of it-it requires Premium but that's cool it's too much fun when I stomp it... Thanks Zippy... Still runs perfect 9 1/2 yrs later, Perfect I tell ya Quote Link to comment Share on other sites More sharing options...
onebadmax Posted March 14, 2014 Report Share Posted March 14, 2014 It's nice to see zippy posting on here again. I sure appreciate him sharing knowledge. Quote Link to comment Share on other sites More sharing options...
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