thin oil in the USA

[zaffo oxnard]

I have always used a universal 15w40 engine oil in my cars because I buy in gallon jugs for my boat which has 15 liter Cummins diesels. Whether it was a 1.9L Escort that went 275,000 miles on Orange Fram filters without a problem before I sold it (30+ mpg. and clean as a whistle when I pulled the valve cover - not even the brown coffee staining) or my 2001 ST, I have simplified to one oil and run without a hitch.

I have seen many comments about blowing out seals with this thick oil, but luckily I live in coastal southern california where a night in the 40s visits us no more than 30 days out of the year at most. Never a hint of a problem. I go against Ford's recommondations and would have had a probelm if I had a lubrication related failure and they asked for receipts for the oil I bought to do the change at home. I know I'm going against the grain, but I'm willing to do that.

Now, I have to ask.... Is is at all harmfull to an engine to use an oil thicker than stated in the book? I can't find a shred of evidence that it is. Never seen or heard of a blown seal. The energy conservation lobby and CAFE are what have driven us to 0-w20, etc/; along with tighter tolerances in the engines. However, If you look at the latest engines from Cummins, Yanmar, Volvo, Detroit ($30 to 60K for an engine alone!) they still recommend 15w40 lube oil. The tolerances in these engines are closer than most automobile engines because of the hp they generate. Granted diesels need different additive packages, but these could be put into a lighter oil like 10w30 or 5w30 if the mfr. who warrants the engine thought the operators would enjoy and extra 1 - 3% fuel efficiency gain, but they don't. They still say 15w40 is best as long as it isn't below -20 or so. Even further along this same ramble, I was just in Australia and saw a couple of 2003-2004 Holden (GM - Australia) Monaros which have the latest Chevrolet 5.7L 350s in them, and they were running 20w40 or thicker oil. When I was in spain last year, Castrol and ELF all appeared to be very high viscocities - up to 60 weight that are being used in little tinly Euro cars. If US cars NEED very thin oils, and the engines are the same as the ones sold elsewhere on the planet (and we change the oil at 3 - 5K miles - what a joke - they go 10k or every year in Europe and Oz) and run just fine, why are we pouring these oils and even synthetics into our engines? Have we all bought into the RoyalPur, Ams(Zoooooomm)Oil, MobileUNO marketing hype? Has the Govt. bamboozled us into thinking that ECII oil is "better". I have to wonder. I bet Ford / GM/ DC almost never pay out for a lubrication related warranty failure. Sure, 1 in 100 lemons are out there, but is is not like 10% of all engines die and untimely death if the oil is changed and regular PM is followed.

Mercedes got famous for for engines that lasted a long time, but they had 2 gallon oil pans on 3 and 4 liter motors and huge oil flilters that came from their 8 - 10 liter truck engines and always recommended 20w50.

I have to think that Flavor Flav and Chuck D were right - don't believe the hype.

Yeah Boyeeee



Ahem,

and now back to our regularly scheduled program.

 

[Bill Ellis]

Oil weight recommendations are just that.......recommendations. I doubt you will ever have a problem going to a higher weight oil; e.g, from 5W30 to 10W30, 10W40 or even 15W40. Oil pressure is not affected since that is determined by a regulator in the oil pump. Cold flow might be a factor when it gets really cold. In old cars I've owned, I used to change the oil once a year. Never had an oil related failure; just really dirty oil. All the hype about synthetics and such is moslty just that too.......Hype. Heavier weight will lower mpg a small amount...maybe...depends on driving style; but will not blow seals and destroy the engine.

 

[Keith McElroy]

I think it is really based on the type of driving you do. I have seen a Ford F150 with 375,000 miles have an engine that looks pristine because the owner changed the oil every 3,000 miles, as well as a Rolls Royce with over 1,000,000 miles (complete with manufacturer certification badge to prove it) that looked pristince because of 4,000 mile intervals. On the flip side, I worked on a ford mustang that had grooves in the cam (and a broken cam follower) because the owner changed the oil at 10,000 miles and drove mostly city.



If you drive highway, you can usually get by with a longer oil change intervals, but if you drive in the city or tow with it, you had better do it sooner.



As far as oil weight goes, I got bit one year because I decided to use a SAE 30 oil that was on sale instead of the 10W30 in a 4-cylinder. Worked great until the temperature dropped, then the starter did not have enough power to turn the engine over. In the northern states, the recommended is best.

 

[Johnny O]

Mostly it's for mpg and CAFE purposes. In a warm climate it doesn't matter so much, here right now it's about 25* and the wind chill is near 0*. I do subscribe to the theory that modern engines have tighter tolerances than those of 20 or 30 years ago and a thinner oil will flow better into the nooks and crannies, especially when cold. With modern oil technology, thick oil is not necessarily good and thin oil is not necessarily bad. What matters is how well it holds its intended viscosity. The idea that you need a 40 weight because it's going to thin down when it gets hot to a 20 weight is old-fashioned thinking when now you can get a 20 weight that stays a 20 weight.

Only way to know for sure is to run the 15w-40, get a used oil analysis (UOA), run the 5w-30 of your choice the same miles, get another UOA, and see what the lab tells you about which one your engine likes better.

I use Blackstone Labs, www.blackstone-labs.com .

I have UOA's from my wife's Taurus that calls for 5w-20 and the wear metals are very low.

If you want the same oil for everything, Shell Rotella Synthetic 5w-40 is diesel-rated and doesn't cost an arm and a leg. About $13 a gallon last I looked.

Much much oil info is at BobIsTheOilGuy.com. The subject of Europe using much thicker oils for longer durations has been discussed there before.