transmision surging
#11
If a different grade of gas seems to "fix" it, you are not having a tranny issue. Perhaps you are perceiving it to be the transmission when the engine is the real culprit.
In a headwind, the engine has added resistance to overcome to maintain speed. If there is a knock/predet issue, the engine isnt running at maximum efficiency, and thus is unable to overcome the added strain of the wind; which would slow you down, and make the TC unlock (which would feel like a downshift).
Higher octane gas (premium) reduces knock, which allows the pcm to trim fuel better (when it notices knock, it tries to rectify the situation by adjusting a/f ratio and spark timing, which essentially neuters the truck). Better fuel trim nets better performance, which translates to being able to overcome more resistance.
#12
#13
If a different grade of gas seems to "fix" it, you are not having a tranny issue. Perhaps you are perceiving it to be the transmission when the engine is the real culprit.
In a headwind, the engine has added resistance to overcome to maintain speed. If there is a knock/predet issue, the engine isnt running at maximum efficiency, and thus is unable to overcome the added strain of the wind; which would slow you down, and make the TC unlock (which would feel like a downshift).
Higher octane gas (premium) reduces knock, which allows the pcm to trim fuel better (when it notices knock, it tries to rectify the situation by adjusting a/f ratio and spark timing, which essentially neuters the truck). Better fuel trim nets better performance, which translates to being able to overcome more resistance.
In a headwind, the engine has added resistance to overcome to maintain speed. If there is a knock/predet issue, the engine isnt running at maximum efficiency, and thus is unable to overcome the added strain of the wind; which would slow you down, and make the TC unlock (which would feel like a downshift).
Higher octane gas (premium) reduces knock, which allows the pcm to trim fuel better (when it notices knock, it tries to rectify the situation by adjusting a/f ratio and spark timing, which essentially neuters the truck). Better fuel trim nets better performance, which translates to being able to overcome more resistance.