I was wondering what you guys thought about putting 5/20 in the older vehicles where 10/30 is recommended?

 

There is an service bulletin that says it is ok to use 5w20 in some of the older motors. I read it and am now using 5w20 in my 97 Mountaineer with a 302 v8.

 

Personally, I would only use a 5w20 in an older motor during winter conditions, in the snowbelt, Canada, ect.

Otherwise, I'd stick to 10w30. However, if it's okay as stated via TSBs, then I see nothing bad about it.

 

I have used 5w20 synthetic in the 95 F150 5.0 for 1 year with no problem.

 

Edit: Dang the page went nuts, throwing all kinds of messages, then posted its self!!!!

Depends on a number of things with older engines.

Things like what type engine, gasser or diesel, how old it is, what kind of lifters it has, it's oil pump, is it using, or leaking oil, the kind of driving you'll do & what kind of weather temp extreems, the service grade of oil you want to change to & does it say on it's container that it's backwards compatable with all previous service grades.

For instance my 94 Taurus 3.8L is specified for 5w-30 preferred, but can use 10W-30 down to zero F, but is on Fords TSB list of engines, to be able to use 5W-20, but my 99 Ranger 4.0L isn't on the list for 5W-20, so I hear because it's oil pump can't keep up needed flow rates with the lighter oil at hot temps & would need to be up graded to use the 5W-20.

Flat tappet cam engines need more zinc & phosphorus than is in most SM lubes, so one must carefully choose, to cover older engines needs. Many high mileage recipes in the 10W-30 synthetic formulas have enough, but I don't remember seeing a high mileage 5w-20 recipe being in the high mileage listings.

If your going to switch to a 5W-20, I'd call or E mail the manufacturers hot line & get some updated input from them on which of their current recipes has your engine type covered, for the type of driving it'll do, under the upcoming temprature conditions, over the next OCI.

The Ford TSB's (I believe there are two, one listing engines that can use 5W-30 & one listing engnes that can use 5w-20) can be found in the F-150 full print out TSB section, as the TSB's covers all models of vehicle engines, not just the F-150.

Just some more thoughts for pondering.

 

If you read the label on the 4 brands of 5W20 I have seen say " Do not use in engines that do not recommend 5W20! "

Right off Castrol's site!!!

<!-- Begin:Added for TB07--> <!-- End:Added for TB07--> Grades <!-- Begin:Added for TB07--><!-- End:Added for TB07--><!-- End: M_G3_Page Title --><!-- Begin: M_A23_Heading Image container --><!-- End: M_A23_Heading Image container --><!-- Article Heading and image --> SAE 5W-20: is <!-- END: Addition of header tag for TB07 --><!-- BEGIN: Addition for TB07 -->a premium, multi-grade oil, providing cold start protection with Exceptional Fuel Economy. SAE 5W-20 exceeds API service SM, SL, SJ and SH, as well as exceeding ILSAC GF-4/GF-3/GF-2 for API Certified Gasoline Engine Oils. Exceeds Ford specifications WSS M2C153-H and WSS M2C930-A. Exceeds the service fill requirements of Ford, Honda and Chrysler where SAE 5W-20 motor oil is specified. SAE 5W-20 should only be used in vehicles where SAE 5W-20 is recommended by manufacturer.


That really means original recommended as 5W20 is for engines with low drag rings for better fuel efficiency and emissions.

 

AND we should not forget that the Oil Pump needs to be designed to be able to keep up with the engines Gallon/Minute Flow Needs, At Operating Temp, while trying to pump a lower viscosity lube, not all can!!!!

The flat tappet engines also need the extra Zinc & Phos, for cam lobe wear protection, that low friction, low sheer roller lifter engines don't require.

Older, solid lifter flat tappet cam engines, shear & beat the oil to death, over their OCI & their worn rings don't seal as well & pass more putrid blow-by products, that the oils add pack needs to be able to deal with & they likely have seals & gaskets that weep.
So we should be mindful of these things & condider the use of a lube whos recipe has been properly formulated with a stronger add pack to deal with these conditions, like having a higher base number, viscosity, Zinc & Phos levels & seal conditioners, ect & many "High Mileage" formula lubes do!!!!

Just some additional thoughts for pondering.

 

High Temperature High Shear viscosity is another variable that has not been mentioned, but maybe implied. XW-20 is 2.6, where XW-30 is 2.9. Not much difference unless that is just enough to protect the cam. Maybe that is why the Ford 4.0 V-6 (made in Germany) was never approved for 5W-20.

Jim

 

I've read that the reason the 4.0L isn't rated to use 5W-20, is because it's oil pump needs to be up rated to handle the engines volume needs & can't do that trying to pump the lower viscosity 20W at operating temp.