Every car forum has an oil change thread. Oil has it's own forum. bobistheoilguy.com. I drive an F-150 with about 100,000 miles. I am the fat guy in a tank top, ballcap turned backwards, driving by myself in a lifted truck with big tires. As the ex said, "this is not a date car!" Holiday weekend under Covid lockdown. My log book shows last oil change in Nov 2019, and about 2,500 miles. This time I used Havoline. A $CVX product. High mileage formula. Synthetic blend. I have a ball valve spigot. Oil changes are literally as easy as turning on the tap.
My regular driver was a 1993 F150 with the 5.0L, a 4-inch lift, and Cooper ATs. Got around 220k on it but good compression on all eight. The right exhaust manifold has a crack which I intend to replace and the rear main seal leaks which I might fix, dunno yet, but I think that truck will go to 300k easy. This past spring I bought a near mint 1995 F150 (5.0L) with 28k miles and a fresh oil change. I had a blow out on one of the well treaded Michelins. I looked at the date code and figured out they were the original factory tires, 25 years old. So I replaced them all with new Michelins. So now I'm approaching 5000 highway miles on that fresh oil. I think I'm going with regular oil since I've heard synthetic may affect the seals. Any truth to that?
Synthetic oil doesn't damage seals. Synthetic oil has better detergents, and does not degrade the same. Synthetic oil will last longer, and do a better job of cleaning out the engine. I had an Explorer with the 5.0. it went 500,000 + miles on original engine and transmission. Factory specification was 5W30. Then Ford issued a technical service bulletin changing oil specification to 5W20. Dealer replaced the sticker under the hood and oil fill cap to read 5W20. Now Ford lists 0W20 as an alternative in new owners manuals. Brand is not so important, unless you are loyal to a particular brand. Correct weight is more important. The most important is that whatever oil you buy meets manufacturer specification. With Ford, almost every oil with the API STARBURST or API DONUT will work. Read the bottle. And change the filter. Often overlooked is changing transmission fluid and gear oil. A running engine is useless if the transmission fails or rear end fails.
I'm really fussy about oil. There are only three brands I will use. Mostly I run Rotella. Bob speaks highly of it but that has nothing to do with why I run it. I've been running baby VW diesels for a long time. We do a lot of highway driving. My Golf TDI ran forever. It was the ALH series which are known to commonly be capable of easily doing 1M miles and still being nicely running and driveable. It was more forgiving with oil. There were several oils that were said to be good for that car, although I only used Rotella and an oil from the Coop. My current Jetta Wagon TDI is more fussy and these engines, while nearly identical to the ALH, are known to have cam wear issues so I have no expectation of it doing 1M miles or anything close. Consensus seems to be they are good for 350~500K miles, or so, before needing a cam replacement. Mine has 190K miles. I've long prided myself on being frugal with money. The Jetta Wagon has half the miles the Golf did when I got rid of it but I will replace it at the next opportunity. It's still a very decent and dependable car but I'm getting less prideful, as I get old. If Tesla's rideshare service (or anyone's) comes out at a semi-reasonable price, we will drop back to being a one car couple. The car will be used only for highway trips, so I might just get a newer Jetta Wagon with a lot less miles. We currently own three vehicles for two people. My truck is a diesel 1 ton from the 1990s so it takes whatever diesel oil is cheaply available.
VW diesels have oil specification which isn't met by some over the counter brands. When you are buying oil, you have to be careful about reading the labels. You don't want to grab whatever is on sale, like I do, only to find it does not meet the spec.
Oil for gas trucks? This is such a marketing scam. As if it was special, and you can't use it in a car.
It probably has a higher thermal breakdown tolerance. The reason I went with a diesel is so I can tow a big trailer on a hot day. I've never seen the temp gauge move above normal but my friends with gas trucks see high temps all the time towing in the heat. Oil breaks down when hot.
I like diesel. When you need a job done, diesel is the better choice. Gas truck dash gauge is a "dummy gauge". Older cars and trucks depend on The fan to cool radiator fluid. Cooled radiator fluid passes a heat exchanger, which in theory, reduces transmission fluid temperature. The needle could also rise if transmission temp is high. For whatever reason, gas trucks and Jeeps are built with less than optimal cooling systems. They are fine for daily driving. Under load, a lot of trucks need auxiliary cooling. In off-road conditions, older Jeeps also heat up. Weird since trucks are supposed to carry load, and Jeeps are supposed to be offroad. Some trucks are sold with extra coolers as part of a row package.. Some newer trucks use modern electric fans triggered by temperature sensors to regulate operating temperature. In older cars and trucks, I install electric fans and coolers. Amazing difference. Especially with transmission temperatures.
In theory, all synthetic oil, regardless of brand, should have a higher tolerance and last many thousands of miles more than a conventional oil. In theory, most conventional oil tolerates between 250 to 300 degrees Fahrenheit. Synthetic oil supposedly is good to 400 to 450 degrees. Thermostats on most gas cars are around 190° to 195° for coolant, and about 185° - 190° for transmission fluid.... Most modern vehicles are engineered to operate efficiently below 220° cylinder head temperature, and 225° transmission temperature. Modern cars have a complex system of sensors and electronically controlled valves to regulate correct operating temperature. No car or truck engine reaches high enough temperature to "cook" the oil if the cooling system operates correctly. Older cars were engineered to keep temperature higher for efficiency and the risk was overcooling. Most engines should work just fine with even the lowest cost conventional oil. Modern cars are often engineered to use lighter weight, synthetic oil to increase fuel efficiency and extend the oil change intervals. A car from 50 years ago using 10W40 conventional oil called for 3,000 oil changes. 25 years ago, 5W30 synthetic blend oil allowed for 5,000 mile oil changes. Today, 0W20 full synthetic goes 10,000 miles. You do not want to buy a new car, fill it with 10W40, then change it every 3,000 miles.
