What did you do to your NNBS GMT900 Tahoe/Yukon Today?

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Wes
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These photos look more like the kind of tubing I would want to do.
they do whitewater rafting on it you can book a trip in Gardener
the yellowstone area is part of the continental divide, the yellowstone river flows to the Missouri river, some of the other rivers flow to the pacific and some flow to the gulf of mexico. passed over it a few times while in the park. we had booked a all day tour which was from 8am to 6pm the guide talked about the park the whole time it was very informative. I think we rode about 200 miles or more thru the park and I drove another 200-300 myself, still only saw a small fraction.
 
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alpha_omega

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Two times now I have fueled with Mobil fuel and noticed my Burb doesn’t run as well. It develops a hesitation getting back on the throttle after coasting. It goes away with a change in fuel. So I put in 18 gallons of E85. To burn on for a few days. Wonder why it does that.

Try this stuff out, it’s the best I’ve found so far. Otherwise some good ole Lucas or a bottle of Redline.
 

alpha_omega

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interesting.. used to have a chevron card for years but their gas was always expensive and I never noticed it being any better than anything else so we ditched the card at some point. only gas I ever really noticed was that one station and that car. it was a manaual tranny so you could feel everything thru the shifter.

this yukon isn't rated for e85 or I'd run it, since there's a station near by. weird because you think a hybrid would and I doubt anything in the fuel system is different than the normal one. must be a tuning issue, since it uses it own ecm. but it also doesn't require 93 either thou, it runs fine on everything. I towed on 87 getting 13mpg lol.

it also doesn't idle when stopped so it's hard to feel idle roughness and since the cam in these has like no off idle tq. the tranny let's it have rpm anytime under a load so it doesn't lug around low rpm where it needs good fuel either.

always been interested in mpg
Do you fluctuate between regular and premium? I can’t speak on the 5.3l, but I can say for the 6.2l (2011 and 2020 Denalis) it should be fed premium. I notice the change when my wife is driving and accidentally fills up with something other than premium. Since I bought her that turbo, she hasn’t made that mistake because her car now takes prem as well.
 

j91z28d1

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Do you fluctuate between regular and premium? I can’t speak on the 5.3l, but I can say for the 6.2l (2011 and 2020 Denalis) it should be fed premium. I notice the change when my wife is driving and accidentally fills up with something other than premium. Since I bought her that turbo, she hasn’t made that mistake because her car now takes prem as well.


mines the oddball, it's a aluminium 6.0L. so not the 6.2 rectangle port heads, they are lower flowing heads, the Cathedral port ones. I read they have better air speed at lower lift. I don't remember the number on them but basically the ls1/2 style head. basically they fill the cyl better at low rpm but give up hp to the 6.2 head up top.

the cam is a weird one too, it's a hybrid thing, not as good as the prius twin cam setup where it can control the timing of both cams separately, but it's the pushrod version, late intake valve closing grind. basically it bleeds off cyl pressure a bit at low rpm, giving up tq off idle for efficiency in the higher rpm band, higher being like 2k. so to over come that it does have a higher compression ratio than the normal trucks, but it still doesn't call for 93 because it bleeds that off and the tranny doesn't ask for power at low rpm. peak tq is usually where you need higher octane. it's got electric motors for low speed and the tranny let's it set in the efficiency range of the cam and basically acts like a cvt pulling the truck along without the rpms needing to rise and fall. think of it as you're requesting how fast you want the truck to go with the throttle pedal and it doesn't a bunch of clever things to give it to you. feels completely different than a standard auto switching thru gears but not like a true cvt either. since those have zero tow rating. to me it feels like a huge thing that just glides down the road without feeling like it puts any effort into it. it's even different than my electric car feels. those feel more directly tied to the throttle pedal, these almost ever so slightly feels like a turbo car without the lag.

yeah I know, to much haha. but yeah. it's different to say the least. some people have said they have seen a mpg more on 93 than 87. but I'm not sure it's true, cause why would it be if they put that much effort to run 87 plus it's over a 1$ more a gal. take a lot more than a mpg to offset 4$ vs 3$ a gal in a daily driver that never even sees half throttle.
 

j91z28d1

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Try this stuff out, it’s the best I’ve found so far. Otherwise some good ole Lucas or a bottle of Redline.


you guys ever try this stuff?


I've read some good stuff about it, but never tried it, since I don't have anything right now that wants more than 93.

more of a drag racing thing. but last i looked summit sold it and had good reviews and tests.
 

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