Probably a stupid question, but why can't I find a regular conventional oil in 5W40. I can only find a synthetic 5W40. In my old vehicle that has only had conventional, I prefer to stick with conventional oil. Is there really much of a difference between a 5W40 and 10W40. I am thinking about during hot summer months, in a pathfinder 3.0V6.
Regular 5W40??
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There are no 5w40 conventional oils.
A conventional 5w40 would really be stretching things VII-wise and would result in an easily sheered oil. You don't want a 5w40 conventional, but could simulate one (maybe) with a 5w30 and two bottles of STP (aaaaaaggghh! No don't do it, you'll ruin your engine.)
for warm weather in an older engine is a 10W40 better than a 10W30. Also, is there a semi-syn 5W40?
Here's an option:
Winter: what you've been doing using.
Summer: mix 15w40 with whatever you've been usng but make them same brand (Like Chevron Delo and Chevron Supreme, etc).
There are no mineral 5W-40 oils currently because they would be unstable viscosity-wise and oxidative-wise.
Winter: what you've been doing using.
Summer: mix 15w40 with whatever you've been usng but make them same brand (Like Chevron Delo and Chevron Supreme, etc).
There are no mineral 5W-40 oils currently because they would be unstable viscosity-wise and oxidative-wise.
In the hot summer months, just use 15W40.
Depending how close pathfinder is to the Arctic circle, that might be inadvisable - "summer" notwithstanding...
pathfinder:
Shell Rotella T 5W40 synthetic is a Group III product. While it is advertised as a synthetic, it doesn't have a lot of the fancy non-mineral fluids that you'll see in Mobil 1, Amsoil, Redline, etc.
Shell Rotella T 5W40 synthetic is a Group III product. While it is advertised as a synthetic, it doesn't have a lot of the fancy non-mineral fluids that you'll see in Mobil 1, Amsoil, Redline, etc.
I was thinking Shell RT myself - in this case it would appear the "synthetic" marketing isn't working as an advantage.
And as far as it being a good year round grade...is the engine worked long enough to get the oil to temp.? Being a HDEO it probably has less friction odifiers, further dropping engine fuel efficiency that the general PCEO user has likely grown accustom to.
Why are you feeling the need to increase oil viscosity - seeing low oil pressures?
And as far as it being a good year round grade...is the engine worked long enough to get the oil to temp.? Being a HDEO it probably has less friction odifiers, further dropping engine fuel efficiency that the general PCEO user has likely grown accustom to.
Why are you feeling the need to increase oil viscosity - seeing low oil pressures?
to be honest it has never seen anything other than regular 5W30 regardless of the season. Oil pressure is about 33psi when driving, 15 at idle. I am curious if it would go up with a thicker oil. My drive to work is about 20 min in the city, with mostly city driving and the odd long 300 mile trip. During summer months (from 40-80 deg fahrenheit) my owners manual actually recommends anything from 10W40 - 20W40, doesn't even mention 5W30. It does use some oil (no blue smoke) about 2 quarts every 4000 miles. Any thoughts?
My F150 was getting about 35 psi hot at 2000 rpm and 16 psi idle with 5w30. Switched to 10w40 and get 40-42 psi hot at 2000 and 18 to 20 psi idle. I would expect you will see similar increases.
If I am correct, increased oil pressure with a thicker oil may mean reduced volume of flow vs. the thinner oil. Thicker is not always better.
I would recommend Shell Rotella T synthetic 5w-40 any day. Fantastic product. Many of my air-colled Porsche 911 buddies have been using the stuff with fantastic results. It is indeed group III but, it is the same base stock Ferrari uses in their formula 1 race engines as well as Ferrari's base stock factory pour in their street machines. Buy it, use it, love it.
Correctomundo. Higher oil pressure isn't necessarily a good thing.
Thicker gives higher presser, lower flow velocity, but thicker oil layer in the bearing (withing the constriction of the bearing clearance). Thinner gives lower pressure, higher flow volume, but thinner oil layer in the bearing. It's a trade off. Generally there is a wide margin (Haynes' manual lists anything from 5w30 up to 20w50 for an 80 - 96 Ford Pickup, with corresponding ambient temperature ranges), though it may be much narrower with some of the newer engine designs.
What is important is a sufficently thick oil layer in the bearing, not the thickest you can possibly get. There are other parts of the engine that might depend on oil flow for cooling purposes, etc.
Extrapolating from '80-'96 Ford Pickups and air-cooled 911 Porsches is less than fruitful too. Much better to look at data from the same year make/model/engine.
Extrapolating from '80-'96 Ford Pickups and air-cooled 911 Porsches is less than fruitful too. Much better to look at data from the same year make/model/engine.
I would not have any problems about running a 5W40, especially in this engine as it is hard on oil (it may stand up a little better). The only thing I wonder about is the possibility of engine leaks with syn. Vehicle as never had syn oil. No leaks currently though. Maybe in the summer a regular 10W40 would better or ok? I could not find much data regarding the same vehicle.
pathfinder,
I agree with TallPaul, your oil pressure is way to low. You need to be in the 40+ psi range with hot oil. That 10W-40 recipe he mentioned, sounds like a winner.
I agree with TallPaul, your oil pressure is way to low. You need to be in the 40+ psi range with hot oil. That 10W-40 recipe he mentioned, sounds like a winner.
Pennzoil and Valvoline Maxlife 10w-40 are a little thinner than other 10w-40's so they're the closest you can get to a "regular 5w-40".
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