Good reason to run a 6.2 on premium fuel
- Thread starter Geotrash
- Start date
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just because it says E85 does not mean you're getting 85% ask the gas station clerk for the data on that..... they should have the percentage on the work order sheet....Here is a clip I took this morning with a full tank of E85. The percentage is about 80% ethanol. My virtual sensor says about 59% this morning.
I didn't display all eight cylinders as I wanted to see the TP% and RPMs to compare to previous tests.
What I found out is the engine still hits the knock sensors when accelerating but far less than the 87 E10 I was testing in previous clips. In normal around town driving with normal acceleration I never picked up the knock sensors lighting up, only on sustained hard throttle situations, going up hill.
I will test E10 91 octane next.
the rattling came from inside the SUV
same been using 91 (highest available ) since i got it... it gets way better gas mileage on the highway pushing 23mpg on it with V8 mode... not too bad for a 6.0L engine The best i had ever done was 32.1mpg but that was taking a country road I was going under 30mph and down hill for like 10 miles so it was in EV mode
I checked it with a bottle tester.
No from outside. And I noticed better gas mileage. In the end I guess it evens out. You spend up front but less frequently.
swathdiver
Full Access Member
The highest you can buy at the pump is 83% alcohol content. Sunoco sells E85R which is a full 85%. Whenever I have asked I'm met with a blank stare and the phrase, "I dunno".
iamdub
Full Access Member
I was about to say- The few times I've asked, they've all just shrugged and pretty much said something along the lines of "we get whatever they fill the tanks with".
The only way to know is to sample it.
swathdiver
Full Access Member
Exactly!
tom3
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Didn't read all the posts, but I'm guessing that motor was on it's way to 300K miles or else it was very much neglected?
ask the trucker he has to know what he is transporting
I don't think there is anyway to know. In the video he clearly states he doesn't know the origin of the engine. He does state that he sees tons of the 6.2L's with broken pistons.
I think that sounds a little inconvenient.
This is how I do it. I take it right off the rail. The good news is my virtual sensor is only off 11% this tankful.
iamdub
Full Access Member
The chances of me being at a station with my Tahoe at the same time the tanker is there is virtually nil. Also, whatever they're delivering will be mixed with whatever's remaining in the ground tanks, so the averaged alcohol content will still be unknown. Also, whatever I'm pumping from that pump will be mixed with whatever's currently in my tank. So, the only way to know what you're burning is to sample some from the fuel rail.
If you wanna know what's coming outta the pump, you'd have to pour a small amount in a container to test. This still would be easier than trying to ask someone that couldn't care less.
Sounds right.
I started out using a one gallon gas bottle to catch some while pumping. After getting home, I would pour the proper amount into the bottle and check what I had pumped in.
RecentlyI have found taking the sample off the fuel rail is very neat and clean. I use my pressure gauge ******* to the schrader on the rail. I start the truck up and use the dump valve to meter out exactly what I need in the bottle after adding water.
By just bumping the dump valve very precise amounts drip out the hose into the bottle. It is actually really easy to get very precise with no spillage.
The really nice thing with the above approach is I am getting what my sensor is seeing with no math and guesstimates needed.
swathdiver
Full Access Member
Tsk tsk on using them dirty words again!
Did a 0-40 on pump gas to show her knocking with 93 octane:
6.2 vs 5.3 and premium gas
Any body have any regrets getting a 6.2 liter over the 5.3L and must you use premium gas in it? im not as concerned with the cost of the gas as is the requirement to use it. I have an 01 LT with a 5.3. Its tuned for 93 and changed all my shift points with no speed limiter. 4L80E Any body...
www.tahoeyukonforum.com
Yeah, seems I should have said "attached the pressure gauge to the Schrader...", we don't want to trigger anyone.Tsk tsk on using them dirty words again!
Did a 0-40 on pump gas to show her knocking with 93 octane:
6.2 vs 5.3 and premium gas
Any body have any regrets getting a 6.2 liter over the 5.3L and must you use premium gas in it? im not as concerned with the cost of the gas as is the requirement to use it. I have an 01 LT with a 5.3. Its tuned for 93 and changed all my shift points with no speed limiter. 4L80E Any body...
Thanks for recording that. Do you run a stock tune?
I am down to a few gallons in the tank and thought I might give some E10 91 a try (I planned to reset my idiot virtual sensor now that I know it will be below 10% Ethanol). I will run the same test with the 91, I bet I get some knocking though. It will be interesting to see if I get more or less than the E85.
swathdiver
Full Access Member
I believe that the tune is stock in the Sierra. Checked with BlackBear and they hadn't done it and it idles low and the shift points are reminiscent of mine when it was on the stock tune. But boy does she giddy up and go! 4.8 seconds to 40 mph (corrected for tires) weighing 6700 pounds last night and I think the tires spun a hair off the line too.Yeah, seems I should have said "attached the pressure gauge to the Schrader...", we don't want to trigger anyone.
Thanks for recording that. Do you run a stock tune?
I am down to a few gallons in the tank and thought I might give some E10 91 a try (I planned to reset my idiot virtual sensor now that I know it will be below 10% Ethanol). I will run the same test with the 91, I bet I get some knocking though. It will be interesting to see if I get more or less than the E85.
I ran the old gal way down and filled her up with Phillips 66 - 91 Ethanol Free (it took 22.8 gal, crimany it was like $110!). I have not found 93 anywhere here. I used the Tech 2 and did a recording of the knock sensors, etc., like I did with the E-10 87 and E85, the knock sensors seemed just about as active as the 87 octane clip, maybe it needed to get up a little higher in the load range before firing, but still real active. I will post it up when I have the time to upload it with YouTube.
Crazy old thread but I just tore down my L94 that was very locked up (no rotation at all), and I appears the root cause of the engine damage may have started with a dropped intake valve seat that took out the #1 piston and cracked the small end of the conrod. I understand valve seats can loosen up if the engine is overheated or there's a crack between the seats. I don't have the history on the circumstances of the problem (PO is NLA), but the truck does have a new looking radiator so I suspect it may have been run hot or overheated at least once and that may have initiated the failure. I'll have the 823 head checked out by my machinist to see if it's repairable, but just wondered if my guess work makes sense to others with more experience with this motor and piston failures.
