Yeah I thought 6 x your body weight sounded high too, but I have'nt heard about an actual scientific study on it. The orthopedic guy who told me that is a guy I have bodysurfed with for a few years, but never really talked to much out of the water, I had no idea what his job was. He came up and ask how I was doing since he knew I had a new hip, and when he sounded pretty educated on the subject, I asked him what he did and he told me he was an orthopedic surgeon, I had no idea....haha, we talked about hip re-surfacing and broken bones for about 45 minutes. He told me that during high impact sports the shock loads on your joints can be 6 X your body weight.
I showed hm my X-ray and asked about the steep angle, heres what HE told me (I've had lots of different opinions, this was his)
The femoral componenet looks good, no issue on that side. The cup is too steep partially because it is also a little shallow on the inside part of the pelvis, he said my Dr. basicly followed the natural lines of my pelvis. The fix would be not only to "rotate" the cup in the pelvis, but also to go a little deeper on the inside, because my operated leg rides a "little farther out from centerline" than the un-operated side, due to the shallowness of the cup. The good news was there is plenty of bone left if a revision is needed. On the wear/metal ion issue, he didn't think wear or metal ions would be an issue but seemed more concerned that I could dislocate easier when my leg was extended behind me and then brought towards the other leg, he thought it could pop out (towards the front) from that position easier than it normally would. He also believed the complete healing process was 1-1/2 to 2 years plus before you should be doing "anything high impact".
UUUuuuuuuhhhh.........enough about me, sorry to ramble off topic haha. Back to running, I think with good shoes and by running on your toes and not bashing into the ground on your heels you could keep the impact somewhat "light" ?? Maybe 1-1/2 times like you say ? and also lessen the jarring impact.