RL 5W-40 all year or 10W-40 in (very-hot) summers?

Jeffrey Behr · Mar 23, 2004

Here's a little 'hair-splitting' for us*.

Porsche seems to be in love with Mobil 1 engineoil. For the Cayenne V8s, P recommends 0W-40 for all temps and 5W-40 and 5W-50 for temps above -13dF. I live in Phoenix which gets REALLY hot in the summer; I've seen many days of 120dF.+ air temps above the pavement, and the LOWS get down to about 85dF. in June - August.

I've settled on Red Line 5W-40 for nonsummer** use but am undecided what I should use for the summer fill; I'll be doing 2 changes per year. I'm thinking that RL's 10W-40 might be a better choice for summer since it has NO Viscosity-Index Improvers, but its slightly lower 100dC viscosity of 14.6 v. the 5W's 15.1 points me toward the 5W. The oils' HT/HS viscosities of 4.7 (10W) and 4.6 are virtually identical as are their warm viscosities of 94 (5W) and 98.

'VII-less' 10W-40 in the summer or 5W-40 all year?

* WOW do we get caught up in the nonsensical minutia of this stuff!

** It's never winter here; it's just not summer for 6 months a year.

buster · Mar 23, 2004

quote:

Porsche seems to be in love with Mobil 1 engineoil

I'd use Mobil 1 0w-40 year round. I think it has more esters in it then the other grades of Mobil 1, like the 0w-20, and a higher flash point. (457 F) The oil stays within a 11.5 cSt to 15cSt range over it's life span, which can be very long. I'm having second thoughts about this oil lately. On a % basis, it's pretty d@mn shear stable considering it's a 0w-40. Your last report UOA was excellent.

With RL, go with either one. The 5w has shown good results so I'd lean towards that one.

[ March 23, 2004, 08:41 PM: Message edited by: buster ]

Doug Hillary · Mar 23, 2004

Hi Jeffrey,

you will get top results like many Porsche owners here do by using Mobil's Delvac 1 5w-40

In this country we get temperatures at least as high as noted by you. Our ambient/ground/pavement temps are very often well above those noted by you

Pilot prototype vehicle testing by many vehicle manufacturers is done in this country especially - in summer - in the Northern Terrirory where there are no speed limits and long high speed roads. Porsche use this area and the Cayenne was extensively tested here prior to its International debut

Porsche like most German makers are indeed very careful about the recommened viscosity range and the temperatures experienced in various export markets. They have been this way for decades

Most Porsche users here use Mobil 1 0w-40,the Cayenne range which is very popular here runs M1 0w-40 too.
Those with a bit more sense use Delvac 1 5w-40

Porsche cars of all models are typically very easy on their engine oils and have been so for some decades - if the maker's recommendations are followed. This especially applies to the Alusil V8 engines like yours which have been in production via Kolbensmidt-Pierburg since 1976-7. These engines and Benz,BMW, VW-Audi and other such structured engines from the same supplier tend to shed heat very well indeed

The Cayenne V6 version will not be sold here due to the high level of competition by other manufacturers. It simply does not stack up against them as value for money

Regards
Doug

[ March 23, 2004, 09:04 PM: Message edited by: Doug Hillary ]

satterfi · Mar 23, 2004

You worry too much.

IMO, RL 10w40 is the perfect all weather oil for folks who drive in above freezing temps.

Patman · Mar 23, 2004

Like Satterfi said, the 10w40 should be just fine for you to use all year round in your climate.

edhackett · Mar 23, 2004

I agree with the 10W-40 RL year round. An oil with no viscosity improvers is the best answer.

Ed

KW · Mar 23, 2004

The M1 0W40 would do just fine. If you want to run Redline either the 5W40 or 10W40 would work well to. Though the 10W40 might be the better choice in your area do to the lack of VI's.

After re-reading your post I see I just said the same stuff you did.

* Man this is like spliting frog hairs.

jperson · Mar 23, 2004

Jeffrey,

I live down in ahwatukee, and drive a turbo volvo.. I run mobil 1 15-50, and I'd would not hesitate to use RL 10-40 or Delvac 5-40. There is no reason at all to use 5 or 0W oil in the summer down here. The oil probably never even goes below 100 dF in your garage over night.

I end up buying any of those three oils, whichever you can find.

BTW, here comes the heat, a little early this year no?

Cheers,
josh

Jeffrey Behr · Mar 23, 2004

quote:

Originally posted by jperson:
The oil probably never even goes below 100 dF in your garage over night.

BTW, here comes the heat, a little early this year no?

Yes on the 100dF overnite oil temps.

And 'too-yes' on the temps. Summer is WAY too early.

Jeffrey Behr · Mar 23, 2004

"The M1 0W40 would do just fine. If you want to run Redline either the 5W40 or 10W40 would work well to. Though the 10W40 might be the better choice in your area do to the lack of VI's."

Sounds like a contradiction in terms to me. Surely M1 0W-40 has "VIIs" in it, so if lack of VIIs is good and that makes RL 10W-40 better than RL 5W-40, M1 0W-40 is the least-best of the three, yes?!?!

"Man this is like spliting frog hairs."

Indeed. Split froghairs are very very fine.

SSDude · Mar 23, 2004

It was my understanding that Redline 5w-40 was Redline's best oil. I believe that there is a thread on this. I would use the 5w-40 all year round and do UOAs.

harrydog · Mar 23, 2004

I've never heard that RL 5w40 is their best oil. Can you elaborate on that?
In my opinion, there is no need whatsoever for a 0w or 5w oil in Phoenix. I'd be using RL 10w40. It's a great choice and will hold up exceptionally well in the high heat of the summer months.

Eiron · Mar 23, 2004

Hi Jeffrey,

I know it's not your preference, but what Doug says makes sense for your location & engine configuration. The M1/D1 5W-40 is an excellent oil for your situation, & if you need more during an outing, some flavor of M1 can be found nearly everywhere.

However, if I lived in Phocalpointofthesun like you, & had a turbo engine, I'd run M1 15W-50 year-round, exclusively.

Cary · Mar 23, 2004

Just a note on Porsche Motors and Synthetic. This months Excellence Magazine has an article concerning Porsche Factory Recommendations for motor oil. The Porsche Factory now recommends for all Air and Water cooled cars from 1973-1998, that they use Synthetic. Porsche also has a recommended oil list, of which there are no longer any mineral oils. The recommended oil list includes mostly 0w-40 and 5w-40 oils with a couple of 10w-40 oils and 5w-50 oils included. There is also a temperature chart for synthetics that allows for 0w-30 to be used to temps of up 95F, and xw-40, x-50 & xw-60 oils at tempuratures in excess of 95F (not the only difference is the low tempurature limits which very depending on if the oil is a 0w, 5w, or 10w).

Cary

Schmoe · Mar 23, 2004

Dude, you gotta go with the RL 10W-40.

SSDude · Mar 24, 2004

quote:

Originally posted by harrydog:
I've never heard that RL 5w40 is their best oil. Can you elaborate on that?
In my opinion, there is no need whatsoever for a 0w or 5w oil in Phoenix. I'd be using RL 10w40. It's a great choice and will hold up exceptionally well in the high heat of the summer months.

This might help:

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=1;t=005783#000005

Grossomotto · Mar 24, 2004

I'm in Tucson, which is basically as hot as PHX. I switched to Delvac 1 5W40 in both Toyota V6 Trucks. All we do is stop and go around town with about 20-30 cold starts a day! The oil gets abused like no other, especially when it's 110 dF in the summer!

I'll just run 10K OCI on them and be done with it. You'll soon be able to get Delvac (Mobil Truck/SUV 5W40) everywhere for $3.99-$5 QT! That's very affordable. There may not be a better oil at any price!

harrydog · Apr 20, 2004

quote:

Originally posted by SSDude:

quote:

Originally posted by harrydog:
I've never heard that RL 5w40 is their best oil. Can you elaborate on that?
In my opinion, there is no need whatsoever for a 0w or 5w oil in Phoenix. I'd be using RL 10w40. It's a great choice and will hold up exceptionally well in the high heat of the summer months.

Click to expand...

This might help:

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=1;t=005783#000005

That thread confirms the opposite of what you said. VI Improvers are not a good thing and 5w40 would be the least desirable choice from Redline, in my opinion.

Jason8691 · Apr 20, 2004

I think Redline claims that their 5W40 has a natural high VI and they dont use improvers. I dont know how true this is, but if it is then it is a better oil than people think due to the lack of VI improvers.

Jason8691 · Apr 21, 2004

Then I stand corrected, I thought I read that in one of their info sheets. But after about an hour of looking I gave up! Thank you Jeff Behr, do you know why they use them in the 5W40 and none of the others?

RL 5W-40 all year or 10W-40 in (very-hot) summers?

Similar threads