Raise the back of your tongue to touch the soft palate. Add vocal cord vibration, then release.

Americans pronounce gasoline as GA-suh-leen (/ˈgæsəˌlin/). Stress falls on the first syllable — keep everything else short and quick. You'll hear it in sentences like "Electric vehicles are gaining popularity as an alternative to gasoline".
Record yourself saying "gasoline" and play it back. The mic stays on your device — nothing's uploaded.
3 syllables, 7 sounds. Tap a syllable to jump to its row, then explore each sound's mouth shape and how it's made.
Raise the back of your tongue to touch the soft palate. Add vocal cord vibration, then release.

Drop the jaw noticeably. Keep the body of the tongue low and forward, and don't let the back of the tongue raise toward the soft palate. Pull the lip corners back slightly, almost a starting smile.

The schwa before L disappears — L becomes the vowel of the syllable. Go straight from the previous consonant to a Dark L.

Pull the corners of your lips back slightly. Arch the middle-front of your tongue high toward the roof of the mouth.

Touch the tip or front edge of your tongue to the roof of your mouth behind your teeth. Air flows through your nose.

Click any sentence to see the full breakdown — every link, every reduction, every flap-T.
The textbook way isn't wrong — it's just not how anyone actually says it.
Stress falls on the first syllable, not the others. Stretch GA — keep everything else short and quick.
Don't pronounce the first syllable too fully. The unstressed syllable reduces to a schwa — the lazy "uh" sound — in casual speech.