CranMaro99

iTrader: (10)

A lot of people say that the mobil 1 5w30, which is what I and many others use, is a bit on the thin side: more like a 5w25.

Then there is the 0w40 from mobile 1, which seems to be a weight that many people use in their LS1's from other oil companies, so I was wondering what the story was on the mobil 1 0w40 weight oil, if there is any.

Thanks!

95TAJade

iTrader: (4)

I tried using Mobil 1's 0w30 once...not really a noticeable difference.

TTA850

iTrader: (7)

All I know about 0w40 Mobil 1 is that it is the recommended oil (and factory fill) in Mercedes Benz and many other euro cars, but they are built with the intent of using that spec oil. Personally I have 82K on my E55 AMG and about to turn 60K on my ML500 (including quite a bit of towing) with no issues and nothing but Mobil 1 0w40 from day one.

intense3123

I work at a Benz dealer and and we have Mobil 1 5W40 in the pumps. I put it in my car since it's free and I've never had any problems. I've never tried the 0W since it's only used for the AMG engines and comes in quarts instead of the pumps. I've pulled valve covers on engines with 150K miles that look great inside cause of Mobil 1. I'm a believer in it.

joecar

I use M1 0W40 and it's fine.

The 0W part is supposed to help oil flow easier during cold startup.

CranMaro99

iTrader: (10)

Yeah I know how it works, but I'm more worried about the 40 weight part.

I hear the 5w30 is on the light side, more like a 25, where the LS1's like something closer to 35. So I was wondering what a 0w40, 5w40, etc would work in our cars.

Starion

iTrader: (5)

The 40 weight should make it a little thicker than the 5w-30 in theory. That is a good thing and if I had a choice, I'd pick the 0w-40 over the 5w-30 given the option. Either way, they're both fine. Don't stress over it.

I've used everything from 0w-30 to 10w-40 without any problems. My only observations are that the thinner synthetics seem to make the already noisy ls1, more noisy.

fleetmgr

Do you know if this was done so it would pass emissions/CAFE standards? I know that was the case with the shift to the 5w oils, just curious about the 0w.

intense3123

We used to have 0w40 in the pumps until last year when the hurricanes hit, one of the Mobil plants or refineries or something was closed for a long time. There was a nationwide shortage of 0w so we had to switch to 5w in bulk tanks and have 0w in quart containers.

CranMaro99

iTrader: (10)

Seems like whatever works, works. I know none of the state weights are better than the other; they're all good synthetics. I was just wondering which may be better for the LS1.

ls1ya

iTrader: (2)

i just add a quart of lucas to it thickens it right on up but wonder what would happen if i
used another half

Carter01

iTrader: (11)

Been using Mobil 1 0w40 since I put my cam in over a year ago. Oil pressure is great, cold starts less noisy, warm idles less noisy, made several 11 sec passes, hit the rev limiter at 6700 many, many times and no complaints. I will use it from now on.

So to answer your question on what the story is on 0w40 if there is one, answer is this oil works great for the ls1 and I have tried it and put it to the test and it performs great!

89LS1RS

iTrader: (1)

the numbers stand for the viscosities at 0 celcius and 100 celcius. the oil will be thinner when it heats up. so 0w40 is a thinner oil at operating temps, thicker when cold. thicker oils stick to metal surfaces better, and protect more on the next startup. the thinner oils free up power and make them better for emissions. the thicker oils protect better.

joecar

Almost everything you said is incorrect (with all due respect)...

0W40 is thinner than 10W30 at startup temp.
0W40 is thicker than 10W30 at operating temp.

The two numbers are at 40°C (left of W) and 100°C (right of W).

At startup you want to oil to flow easily, you want thinner oil when cold, not thicker.

Thicker oil doesn't stick to metal surfaces easier, but hot oil does.

Thicker oil can't protect if it can't flow.

jmilz28

iTrader: (13)

I prefer xW-40 for higher mileage LSs. I use M1 0w40 in mine, but I like Royal Purple better. M1 has been on awesome sales at Advance lately so...

89LS1RS

iTrader: (1)

ok, we were both wrong
Viscosity ratings for commonly used motor oils typically range from 0 up to 50. With multi-viscosity oils, a "W" after the number stands for "Winter" grade oil. The numeric value of the first number (example 5W-20) is a measure of the pour point of the oil expressed in degrees Celsius. The rating is determined in a lab using a cold crank simulator and mini-rotary viscometer test. The oil weight is its viscosity index at 100 degrees C (the boiling point of water).

Black FormulaLs1

iTrader: (10)

all i know is that i only run mobil 1 5w-30 in my formula unless i can get royal purple 5w-30...but that is the only oil my car will ever see..while i own it anyways

wildbird02

I must be an oddball then, because I run Mobil 1 10w30. I have not studdied the weights much. I decided that weight, because of a manual I read from an old GMC pickup. It displayed 5W30 operating temp range (exterior air temps) cut off before 100 deg. F. 10W30 was in excess of 100 deg F, but was not recommended to lower temps below 0 deg F (because it was thicker). Even though I am in the north, I never drive it below 45 deg at the minimum. Of course, I would not be worried about Mobil 1's protection at any temp, because it is excellent oil.

I have been reconsidering the oil weight now that the consuption has went up drastically from my suprise. I burned one half of a quart in 2200 miles! Has me a little stumped. Not burning oil by looking at the pipes. No oil found on the throttle side of the pcv. Dropped the oil and went on a road trip with steady throttle (nothing over 3k rpm). Same oil consumption. Pulled AC delco plugs with only 7k miles on them and just found the ceramic to be a reddish color (no oil or heavy carbon deposits). One mechanic said sometimes oil gets splashed up in the baffles of the valve cover and gets sucked into the pvc system. He told me to run a bead of RTV gasget maker on the baffles to prevent this. Have not done this yet.

What do you guys think? I am going to start this as it's own thread, so please give me feedback on here or the new thread.

02 T/A WS6, M6, dyno tuned, LS1, EGR delete, no cats, SLP LM2, SLP Headers, SLP Lid, 113k miles,

99huggerorangeZ

iTrader: (2)

ive ran mobil 1 5w30 syn since new,just switched to m1 5w40 last year.