"Head" is considered a long "ea" word because the "ea" makes the long vowel sound of "ee" in this word.
about 180,000 w/o proper maintence 999,000 with
The EA has a short E sound in "meant" to rhyme with bent and sent. The EA in the present tense of the verb (mean) has a long sound, to rhyme with bean and seen.
There is no "A" sound. The EA pair has the long E vowel sound as in beat.
The answer you seek is: as long as you do the proper maintence to the vechile it should last forever!
Maintenance
`lubrication
No. The EA in great has a long a sound (grate). The EA in learned has a short E sound.
No. The EA has a long E sound as in beam and team.
No. The EA has a long E sound as in tease.
keep it in good condition
Yes, the word "sweater" has a long "ea" sound where the "e" is pronounced like "ee." It sounds like "swee-ter."