I just got back my recent oil analysis results from Blackstone Labs, and I wonder if anyone can comment on them.

1991 SE-R, 110,000 miles, last 40K using Mobil One 5W/30, oil changed and tested every 3-4K for several years now.

I had a high fuel content (2.3%) in my oil, which probably lowered the viscosity (52.3) and the flash point (320 F.). What concerns me is the higher iron count (31, where average is 18). My highest previous value for iron was 21, so this one is getting up there. What is weird is that my lead reading stayed pretty low (7, where average is 14). I've had lead as high as 18, when my iron reading was 21.

Why would my iron reading be abnormally high, but my lead reading stay so low?
What parts of the engine are mostly iron without lead?
What would cause my fuel content to jump so high?

I've had the higher fuel reading in 2 of my oil samples from Blackstone. Both time wer during the winter with lots of idle time (warming car) and with lots of stop and go traffic from snowy weather. The following oil changes came back normal. This engine has ~170k on it now. I have no comment on the iron as all of my wear metals are unusually low.

The only source of iron I can think of is the cylinder wall liners. I don't know the lead content of these, though. I don't know what the piston rings are made out of.

I'd try and figure out why the fuel is there, fix that, and then have that oil checked to see if the iron level goes down. I think running too rich actually reduces the oil film on the cylinder walls (I don't remember where I read that) but I don't know how rich you have to run to cause that problem.

What parts of the engine are mostly iron without lead?

Pistons, crank, rods, cams....