Riddle me this Batman

[radrecon69]

Riddle #1. Ok as some of you know and some don't I bought a 02 Duramax and it had 60000 miles on it. The other day I was looking at the door frame at the DOT sticker and seen where the tire pressuer is supposed to be 55 lbs in the front and 80 lbs in the back THAT is 25 lbs difference WHY? Can you safely tow with that much air pressure (1976 33ft AVION Alu. camping trailer)?

Riddle #2 Reading Duramax threads I read where some of your Duramax's soot up real fast after changing the oil, Well I have 3000 miles on mine and the oil is still as clean as the day I put it in. Now I use Schaffer's oil and NAPA gold oil filter and the truck generally gets driven back and forth to work 25 miles which 20 mile is interstate, is this something to worry about or be happy?

The last and final RIDDLE, Has anyone ever used or heard of this "Tection Extra Diesel" oil from Castrol?

Rick

[Kennedy]

The tire psi is based on load carrying etc, but I typically run about 10psi more in the front unless loaded heavy. I generally run 60 front/50 rear, but run 70-80 in both if towing heavy on trips.

Soot in oil willalways be there and while color is a way to tell, sometimes black oil really isn't very sooty. What keeps the oil clean is clean combustion from driving respectably and at stock or moderate power levels. In other words if you see smoke/soot out the tailpipe it WILL get into the oil. I've been enjoying my 2005's clean combustion and letting the 02 make the big smoke. My oil stays quite nice although both trucks have my oil bypass setup installed. The 02 definitely gets darker faster, but the soot levels are decent at sampling time.

For synthetic oils, I'd suggest Mobil Delvac 1 or Amsoil 15w40 diesel and marine.

[tanker]

Rick, The tire pressure is set for the GVW of the truck by the manufacturer. Yes you can put 80 PSI in the front, but you will get a real hard ride. The 80 PSI rear is for when you are loaded to that capacity.
My advise is to weigh your truck with trailer, fully loaded with pasengers full tanks, at a "Cat" type truckstop scale. You will then have front axle weight, rear axle weight, and also the tandem axle weight of your trailer and total combined weight. Now get a tire inflation chart for the type and size of your tires, then you can adjust the pressure properly. If you are empty most times, I'd keep the front and rear at about 55 PSI each for a softer ride.
Black oil? Hmmmm, that may be from residual oil left in the engine. How often do you change the oil. I change mine about 2500-3000 miles max and it stays fairly clean. ;)

[silverback]

Rick,
I run 59 PSI front and 65 PSI rear on 265/75/16 Revos when not towing (daily commute routd trip of ~48 miles). When towing our 25' ~6500 lb. Airstream I bump up to 61 PSI front and 68 PSI or better in the rear. It depends on how much I'm putting in the bed along with the trailer. I have been experimenting a couple years to get the right safety comfort mix. I totally agree with Tanker get weighed and base your tire inflation on that. Regarding oil, I'm using the Delvac and it stays clean until I change it.
-Ken

[Jim Brzozowski]

I upped my pressures to 65 frt. & 55 rear and gained about 1.2 mpg over the 55/50 I was running.
Towing heavy GN trailer, I usually run 75ft/80r. Tires are looking great at 65,000. Course I don't run power levels like the fast guys here do. One good burn out can take many miles off those tires. Watch the cornering speed, that's where most tires wear the most in a short time. Think about the distance and loading across the tire in cornering as opposed to the distance and loading around the tire going in a straight line, that really clears up the question of how do I get the best mileage from my tires. Course you got to play sometime, just don't do it all the time if you want them to last.