Havoline Hi-Mi

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Aug 27, 2003
Found some of the Havoline 10w30 High Mileage on sale at Advance Auto Parts the other so I picked up 5qts to try in a 94 Regal. Its got 130K mi on the 3800 in it.

Right now there's Havoline full-syn 10w30 in it. The Hav. syn is much better than the Mobil1 I previously used. Runs much quiter and the oil pressure stays up better.

I thought I'd try the Hav. Hi-Mi since its 12cSt @ 100deg vs. 10.8 for the Hav. syn. Thought it may help a bit more with the oil pressure.

I am concerned a bit about the "seal conditioners" in it. Is it just a small amount of esters to aid in deposit control and seal-swell/conditioning? If so will there be any adverse effect from using it. The car leaks no oil currently.

If the this "thicker" 30wt helps with the oil pressure, next time around I may try a regular dino 10w40 to bring the pressure up even more or something like Rotella T syn 5w40, since no one around here carries the Havoline syn in 5w40.

The hi-mi formula is available in 10w40, but I'm afraid that'd be a bit too thick at 15.8cSt.

[ April 01, 2004, 03:28 AM: Message edited by: Forkman ]
You should check with the Havoline tech folks (should be an 800 number), but my understanding is seal conditioner is to restore the seal from the effects of heat and time which tends to harden the seals. When hardened they can easily develop leaks because they won't flex. The conditioner should soften so they perform more like newer seals.

I boosted my oil pressure (hot 2000 rpm) from 36 to 45 by switching from a 5w30 to a 10w40.
Sounds like good logic to me. I guess the proof will be how the HI-MI will "maintain it's viscosity over time. The M1 is thin, but stays a pretty bullet proof 30W and apparently the Havoline Syn maintains well, too since you have a gauge. The HM might actually thin out.

Sounds about ideal, if it doesn't thin out. Gotta love the 3.8
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