Why is the cation always formed on the carbon near oxygen?

I would think that O would have a -I effect and destabilize the cation. Or is the +M effect enough to stabilize it more than a methyl group?

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    $\begingroup$ By DHP do you mean dihydropyran? DHP can be an abbreviation for other compounds (dihydropyridine, for example). $\endgroup$ – Ben Norris Jan 14 at 16:02
  • $\begingroup$ What is the hydrolysis product of dihydropyran (DHP)? $\endgroup$ – user55119 Jan 14 at 19:18
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    $\begingroup$ Oxocarbenium cations are much better stabilised than "ordinary" carbocations, often beating even allylic or benzylic cations, afaict. $\endgroup$ – Mithoron Jan 14 at 20:56