My experiences with thin oil

[Lazy JW]

Originally Posted By: jaj

As for the metallurgy, the S65/S85 V-engines use iron-coated forged pistons in Alusil bores. Basically, it's the traditional design turned inside out and made really light. I imagine it's easy to manufacture, too. As for longevity, we'll have to wait and see....


Sorta like the Chebbie Vega, eh?

 

[HTSS_TR]

Originally Posted By: Bryanccfshr
...
I agree that to go out of manufacturers specification on oil viscosity or even approvals is not well advised without the owner understanding the risk they are taking.


I agree. I knew the risk of using much thinner oil then spec'd. That why I changed out PP 5W20 to Delo 15W40 in Aug after Vegas trip, that I got stuck at Death Valley for 3 hours with ambient temperature in the 120+.

This car sees more than 98-99% of all trips at less than 15 miles. With this short distance, the oil temperature mostly was at less than 100C (or 212F), except for the summer and Christmas trip to Vegas. I may invest in some oil temperature gauge to see if thinner oil does indeed lower temperature on long trips.

 

[Doug Hillary]

Hi,
HTSS-TR - Thank you for sharing your experiences with us. Surely people reading your Thread should have gained something from the discourse on the subject

Daimler Benz were always a believer in the less viscous and HD lubricants in both petrol and diesel engines - 10W-20 and 20W-20 viscosities were recommended up to 86C in the OM326 (diesel) engine familiy and oil consumption was considered normal at 1 pint per 100miles!

From
Thanks again for excercising our collective minds

 

[jaj]

Originally Posted By: Lazy JW
Sorta like the Chebbie Vega, eh?


It won't be a long wait, will it!

 

[zoomzoom]

Originally Posted By: HTSS_TR
Originally Posted By: Bryanccfshr
...
I agree that to go out of manufacturers specification on oil viscosity or even approvals is not well advised without the owner understanding the risk they are taking.


I agree. I knew the risk of using much thinner oil then spec'd. That why I changed out PP 5W20 to Delo 15W40 in Aug after Vegas trip, that I got stuck at Death Valley for 3 hours with ambient temperature in the 120+.

This car sees more than 98-99% of all trips at less than 15 miles. With this short distance, the oil temperature mostly was at less than 100C (or 212F), except for the summer and Christmas trip to Vegas. I may invest in some oil temperature gauge to see if thinner oil does indeed lower temperature on long trips.


have you done any UOA with thinner oil?

 

[ikeepmychevytoo]

20w-20 seemingly widely mentioned/recommended since the 40's. This is not necessarily the post-war period but earlier documents are hard for my reach. RollsRoyce has a TSB around 40's for approval of SAE 20 lubricants as well as Chevrolet for that era and my '84 v6. Many Chryslers up to 70's may also be noted with 20w-20 recommendation for overall and summer use. Some 10w recommendations for winters.

My manual from '84 recommends the thinnest choice oil for the expected temperatures and lists the thicknesses by the winter (W) viscosities.

After these renditions I noted my engine is also quieter with the thinner oils. 20 weight oils are not plenty here so my speculation is based on the kinematic viscosities at the 100°C specs of the 30 weights. Even visc. differences are small, the more fluent feel of engine and the overall silence is obvious with the thinner side of the 30 weight.

May be some possible coincidence of the thinner oils is with the hydraulic valve pushers, but not all the older engines with 20 weight recommendations have theese hyraulic valvetrains.

 

[HTSS_TR]

Originally Posted By: zoomzoom

have you done any UOA with thinner oil?


No, I didn't do any UOA for either manufacture spec'd oil (0W40) or thinner oil.

 

[Leonardo629]

I've been experimenting with a thinner oil, then I found this thread.

I saw BMW "M" motors mentioned, and I happen to be experimenting with one. I have a 2008 Z4M coupe, which shares the same S54 motor with E46 M3s. Most of you guys know that motor calls for Castrol's TWS 10W60 from the factory, but after reading some UOAs and inputs from fellow members, I decided to switch to Motul 300V 5W40 double ester.

I've been running this oil for 700miles now, and my motor is not blowing up yet...which a lot of M owners say would happen if I do the switch.

Impressions so far:

1)motor definitely feels more lively, easier to rev.
2)butt dyno says power comes on at lower RPM
3)it takes much shorter driving distance to heat up all 5.5L of oil
4)MPG improved a bit
5)high pressure VANOS is still noisy

 

[zoomzoom]

Originally Posted By: Leonardo629
I've been experimenting with a thinner oil, then I found this thread.

I saw BMW "M" motors mentioned, and I happen to be experimenting with one. I have a 2008 Z4M coupe, which shares the same S54 motor with E46 M3s. Most of you guys know that motor calls for Castrol's TWS 10W60 from the factory, but after reading some UOAs and inputs from fellow members, I decided to switch to Motul 300V 5W40 double ester.

I've been running this oil for 700miles now, and my motor is not blowing up yet...which a lot of M owners say would happen if I do the switch.

Impressions so far:

1)motor definitely feels more lively, easier to rev.
2)butt dyno says power comes on at lower RPM
3)it takes much shorter driving distance to heat up all 5.5L of oil
4)MPG improved a bit
5)high pressure VANOS is still noisy


Friend of mine has same M3 he races..he said that engine problems for that model come from defective rods that were used and that BMW replaced his engine free of charge when it blew..

they tried to mask the problem with 10w-60 oil..

 

[jldcol]

I am reading a engine mechanics book and cylinder testing showed piston is not fully coated in oil, well the loaded side almost is and the other is not. A thinner oil coats more of the piston than a thicker one, but the coating is thinner. Even like this the piston does not rub cylinder wall in mid-stroke, it does at the bottom and top dead center though.

 

[Mustang2008Z]

My experience with Mobil 1:

I wanted to throw in my 2 cents worth related to oil and oil changes. What a thrill....huh? A History of my Nissan P/U:

In August, 2000, I purchased a brand new Nissan Frontier P/U, with just 90 miles on it, and I traded in a 1991 worn out Ford F-150 P/U for it, the transmission of the F-150 "died" as soon as I parked it on the lot of the dealership (it was sold off as scrap by the dealer).

Well, I changed the oil, regularly, at the 3k/3 months intervals using Dino oil, 5W-30 Quaker State, Pennzoil, and 1x only Citgo Oil from the dealer that sold the truck to me, then back to Pennzoil, and finally, Conoco Oil from Jiffy Messy Lube, they lost my washers from my air filter housing, after I told everyone there not to touch my air filter housing. That was the last time I ever went to them. Then, in 2008, I went to a small independent mechanic shop very close to where I live, and I decided to try Castrol Synthetic Blend 5W-30 with Purolator Oil Filter. Castrol was very dark after just 3k miles on the oci, and I changed it out around the 5k mark. OEM recommends 3,750 miles/3 months, I think regarding months, between oil changes. Truck has been out of warranty since August, 2003. Well, I changed to Mobil 1 Full Synthetic and Purolator Oil Filter, the oil, this time at 1k was as dark as the Castrol was at 3k. My vehicle has over 84k on it and is about to hit the 85k soon. In my humble opinion, the vehicle seems to run quieter with Mobil 1 Full Synthetic than with any other oil, and the mileage has improved from 22 mpg to 24.5 mpg in stop/go driving. It has even gotten to the 27.5 mpg mark a couple of times in stop/go driving and going 70-80 mph on the expressway. The only time it went down was when I went to the seacoast one weekend in February, 2009, and my mileage shrank to just 17 mpg. I wonder if it had anything to do with sea level and the Exxon Gasoline I used at the time. I, normally, go to Valero for gasoline, Exxon,Chevron or Texaco to fill up, it depends on which gasoline is the cheapest at the time. Valero has been the cheapest for the most part around here. In 2008 I drove my Mustang to the sea coast as well, and it too suffered in the miles per gallon area as well. Something at sea level and the gasoline mixture for sea level causes a loss in mpg, in my opinion.

So, I think that I will continue to use a Full Synthetic in the Nissan, probably Mobil 1 again, with the Purolator Pure One Filter.

By the way, my dipstick is as clean as the day I bought the truck new from the dealer, after wiping off the oil from the dipstick.

 

[tropic]

Originally Posted By: Mustang2008Z
Something at sea level and the gasoline mixture for sea level causes a loss in mpg, in my opinion....

I would suspect the higher atmospheric density before anything else. I get wicked MPG at more than a mile above sea level, but it falls nearly to the EPA sticker numbers when I'm in SoCal.