1996 NA 850 Manual says 10W-30 Why Not 5W-40?

PeteB · Post by **PeteB** » 07 Oct 2016, 16:52

Anyone know why the manual states that the preferred oil is 10W-30 and
not 5W-40 like most modern car engines? I'm planning to switch to Mobile 1
and thought I'd ask before buying. Any reason _not_ to use 5W-40?

Post by **scot850** » 07 Oct 2016, 17:04

It may depend on where you live and the typical temps your vehicle will see. The 98 and older P80's I've had usually gave 5W-30 for winter and 10W-30 for summer. My 2000 R gives 5W-40 as the all around option.

Neil.

Post by **misha** » 07 Oct 2016, 17:45

PeteB wrote:Anyone know why the manual states that the preferred oil is 10W-30 and
not 5W-40 like most modern car engines? I'm planning to switch to Mobile 1
and thought I'd ask before buying. Any reason _not_ to use 5W-40?

No reason at all.Feel free to use it.
I use 10w-40 all year round and sometimes in the summer 15w-50 for moderate climate area.

Both are semi-synth.

Post by **tryingbe** » 07 Oct 2016, 18:05

PeteB wrote: I'm planning to switch to Mobile 1

Use 0w-30.

Post by **misha** » 07 Oct 2016, 18:23

For n/a ....there is no point....besides....it's too thin for high mileage engine.Oil consumption would be doubled with oil that thin in high mileage engine...EXCEPT if you live in extreme cold climate area...then YES for 0w-30.

Post by **sleddriver** » 07 Oct 2016, 19:29

PeteB wrote:Anyone know why the manual states that the preferred oil is 10W-30 and
not 5W-40 like most modern car engines? I'm planning to switch to Mobile 1
and thought I'd ask before buying. Any reason _not_ to use 5W-40?

After doing quite a bit of oil research on BITOG, I settled on M1 10w-30 HM as my oil of choice. I initially went thinner, but oil consumption increased. I think because the older white block motors weren't designed for today's fashionable thinner oils. The sled's oil comsumption is next to nil (especially since I've fixed the leaking front camshaft seals....)

Another oil I often ran was Shell Rotella T6 100% synthetic in 10W-40 I think. I could buy a gallon of it at WM on sale for less than $20! Hard to beat that. I run oil for 8 to 10k mi with a filter change + top up half-way.

PeteB · Post by **PeteB** » 07 Oct 2016, 19:58

Thanks sleddriver, makes sense, we don't want more consumption.

Post by **oragex** » 07 Oct 2016, 20:06

Theoretically, a 5W30 will have less additives than a 10W30 because it has to reach a larger range. Same, a 5W40 will have more additives than a 10W40. The closer the numbers, the more 'stable' the oil in extreme conditions (such as racing).

I run 5W40 because of cold winters (otherwise I would use 10W40) and because I like to rev the engine. A W40 is also quite good in very hot summer climates. I see no reason not to use a 5 or 10W40

PeteB · Post by **PeteB** » 09 Oct 2016, 17:50

I was at Walmart and they had a 2.5 gal bottle of Shell Rotella T6 100% synthetic, that's a very big bottle!

Any opinions on SuperTech full synthetic, they have 10W-30 at a very low price, $17.47 for 5 qts:
https://www.walmart.com/ip/Pennzoil-Sup ... t/16474422

I'm going to check on Bob is the oil guy's site and see what they say. Edit: Comments seem to be okay:
https://bobistheoilguy.com/forums/ubbth ... /1760603/1

They say that it has GM 4718m cert, whatever that means:
https://www.bobistheoilguy.com/forums/u ... er=1275957

Post by **sleddriver** » 10 Oct 2016, 13:13

Here's a link to my motor oil research on BITOG: https://bobistheoilguy.com/forums/ubbth ... /2522572/1. You can also read up on Haas' oil article there.