QuantumRift

Last May, we got a (new to us) 2017 Silverado with the 6.2L 6 SPEED auto. It had 33K miles on it. After we towed our RV on a couple of camping trips, I noticed it was doing that 'vibration' or 'shudder' thing. I got progressively worse and sometimes the shifting would be jerky in low gears in a down shift or upshift 1 to 2 or 2 to 1 shift. Then it would, say around 45 mph, shudder that felt like I was going over rumble strips in the road. Yes it felt it was coming up thru the steering or tranny. I did some research and discovered that this "Chevy Shudder" was a well-known issue that was ignored by GM. Seems that many of the trucks assembled in Mexico, the wrong type of tranny fluid was used, and Chevy just shipped 'em out anyways with no remediation. This would cause shuddering, erratic or jerky shifting, etc and but the time it got that bad, the torque converter was shot and would have to be replaced. I called a couple of Dealers and the were welcoming me to have a look at it, for a fee, of course. I declined and called a local GM dealer and they took it in and looked at at and ended up replacing the automatic transmission - flush and fill some 20+ quarts at no charge, as it has a factory warranty until 60K miles. That, so far, has cleared up the problem, but if it comes back they'd said they'd do the torque converter replacement, as the wrong fluid glazes up everything in the TC. So might want to check that out and see if you too have "The Chevy Shudders".....

You are kinda, well, wrong here - and here's why: Do the math, look at the BTUs per volume: 1 gallon of gasoline is approximately 114,000 BTU. 1 gallon of ethanol = 76,000 BTU. Therefore, gasoline has 1.5 the BTUs available by volume than ethanol. Start with 10 gallons of gasoline. 114K x 10 = 1,140,000 BTU. REMOVE one gallon of the gasoline (10%) and replace 114,000 BTU with 76,000 BTU. Now that 10 gallons of E10 fuel has: (9 x 114,000) + 76,000 = 1,102,000 BTUs available by volume - SO you are reducing only 10% of your volume 50% in BTU. 1,102,000 / 1,140,000 x 100 = 96.7%. so 1 gallon of E10 fuel has 96.7% the BTU content of "pure" gasoline. Extrapolating - if you know your vehicle, when running on PURE gasoline, can get 20 miles per gallon, that 10 gallons will take you 200 miles. Reduce the BTU content by volume and that drops to 96.7% of 200 miles, or 193.3 miles. SO you drop mpg down to just over 19 mpg. You can use the price per gallon etc to calculate the rest. Calculating E15 would be similar, just replace 1.5 gallon of that original pure fuel with ethanol..... Now with a FLEX fuel vehicle, you can utilize any blend as there is a sensor that tells the fuel how to adjust the timing, injection etc. E85 delivers a 25% loss (on average) of mpg as the ethanol in an 85% ethanol/15% gasoline blend has substantially less BTUs available for combustion) on mpg and only saves 20 - 40 cents per gallon, which does not offset the loss in mileage. Around here (Central Ohio), a good station "Sheetz" sells E15. Today, the price of their 'regular' E87 octane fuel (E10) is $3.899. Their 88 Octane E15 sells for $3.599 a gallon, and if you have a SHeetz card you get an additional 3 cents off ($3.569 a gallon). For a NEGLIBILE loss in mpg, and getting 88 octane (for my 6.2L 2017 Silverado), it's a no-brainer. I saved $6 on a FILLUP today and that adds up.