Daily Archives: April 2, 2007

I’m putting diesel in my car from now on.

Diesel oil anyway. The fact that my car has 209,000 miles on it now says something about how well the previous owners have taken care of it. To this day the car doesn’t leak a drop of fluid anywhere. But with as many miles as it has, it’s pretty important to make sure I’m not pushing the envelope. On the oldspower.com forum a bunch of car guys were discussing the best oil to use for our cars. Surprisingly most people said oil for diesel engines was best. They reason why is kinda complicated, so if you don’t really care, please skip ahead to the picture of the ostrich head.

Back in the day cars were far less complicated than they are today. You had all those moving parts grinding against each other, so yesterday’s oil was packed with all sorts of great lubricating agents that worked pretty well. Infact lead was put in gasoline as a lubricant! In a car as the valve closes, it slams against the valve seat like a little jack hammer. And it will do this millions of times over the life of your engine. So they put lead in the gasoline and it would cushion the impact. Then the government decided it was bad to be burning up all this lead and spewing it into the atmosphere. They said, “Hey you can’t make cars that require leaded fuel anymore.” So the manufactures had to start manufacturing hardened valve seats which didn’t require the lead lubricant, but of course were more expensive. So if you’re driving an old car circa early 70’s on back. You’d better have stock piles of leaded gas, or use a lead additive to every tank!

This is much the same story for motor oil. More than dead dinosaurs go into the oil you put in your car, there’s detergents that break down the dirt and crud that can get caked on inside, there’s additional lubricants like ZDDP (zinc dialkyl dithio phosphate). Both are good things for any fuel burning, friction producing motor, and diesel oil has more of both! Unfortunatly the government decided burning and leaking this ZDDP all over the place was bad for the environment too! So they told the car makers and the oil manufacturers that they were starting to limit the p.p.m. of ZDDP allowed in conventional motor oils. This caused manufactures to rethink how they designed the components of your engine, to tolerate the less effective oils now mandated.

This is most important for cars with flat tappet camshafts instead of roller camshafts (the difference). The more ZDDP the less wear on the lobes of the camshaft, and all the other parts of your engine for that matter. So even if you don’t have a flat tappet cam (which I don’t), the benifits of ZDDP are still realized through better overall lubrication of your engine!

So that’s why I’m using diesel oil. You could use it if you wanted. But unless you have a car made before circa 1985 it’s probably not completely necessary, but it’s certainly not doing any damage either. Quite the opposite in fact. And when the price of cars keeps going up and up. Don’t blame GM, blame our good friends in California and the EPA. I am fielding bets though on whether I make it through this oil change though. 2:1 odds says I do. So you give me a million dollars, and if my car blows up before 212,000 miles, I give you TWO MILLION! I take cash or paypal. No personal checks please.