Okay so I have always ran 10w30 Mobil 1 Extended Performance, I never had any problems with that oil.
Every 3000 miles I change it with a K&N oil filter HP-1010. The oil looks good and I dont loose a drop of oil when it is time to change.

Now the last oil change I did 3000 miles ago I decided to put in 5w-30 Pennzoil Ultra.
I decided the lower weight due to colder weather and brand due to alot of people recomending it on the forum.

Well I check the dipstick before I change the oil and the thing read just right above the low mark. No leaks, no burining. The oil looked okay for 3000 miles of use, not burnt at all.
So how could this have happened?
The only thing I can think of is the lower weight of oil and the cleaning additives in the Penzoil.
I guess I will be switching back to 10w-30 Mobil 1 Extended Performance and see if it happens again.

 

Interesting please do follow up

 

Why would you buy extended performance, meant to run 15k miles, and change every 3k? If you change that often there is no benefit to synthetic. Your pocket book would appreciate conventional and your engine wouldn't know the difference.

Also, you should be running 5w30. The 5 is viscosity on startup and, since is thinner, moves more freely then 10.

 

I totally agree! If anyone changes oil and filter at 3K, you should really just use dyno oil, seriously.

 

if my car has 150k miles on it what kind of oil should i be using .. i was running 10w30 valvoline synthetic but at 5k miles i saw it was getting to thin and level was kind of low so i switch to 10w40 synthetic. havent ran the 5k miles yet to check it ...

 

i recently bought penzziol cus they had a promo $5 off and $10 gas card. never tried it but decided to give them a try. anyone else try penzoil? i bought at walmart so i could probably return and exchange it for my usual castrol.

 

Synthetic oil is more resistant to adverse weather and will maintain a consistant viscosity.

I would look for "High Mileage Oil" because it still has zinc. It has been shown on older vehicles that after removing zinc (Thanks GW Bush) it caused excessive internal engine wear.

Look for the API Rating Donut on back of oil bottle, if it says "Resource Conservative" than its zinc free. Other rating should be SM for your car and SN for 2011 or newer.

I use Mobile 1 Extended Performance 10W-40

 

Do you have any oil consumption with the 10w40?

 

This is a very good idea....^....I wouldn't use Pennzoil in my Honda! (lawnmower)
Going back to Mobil1 10W/30 is a good idea and make sure you watch the oil level on your dip stick frequently!
Gary

 

I haven't heard much negative about Pennzoil til this thread...

The real truth is that if you want to know how the oil is doing in your car have a Use Oil Analysis performed and you will know right away.

 

From what I have read penzoil platinum and ultra are better than Mobil 1 and castrol syntec.

 

Would switching to a 5w40 oil help with oil consumption?

 

Pretty sure I've read the opposite on this forum. Ppl have posted used oil analysis from blackstone labs etc. and GC consistently performs.

I always use GC and due to an aging engine don't want to risk too much so I change at 3750miles religiously.

Oh that and the -21F temp here means that no oil but 0w-30 will cut it.

OP try GC and see what sort of result you get.

 

I was talking about standard castrol syntec not gc. Obviously a true synthetic is superior, but most castrol and mobile1 are not true synthetics.

 

Just wanting to help op out in finding the right oil by being more specific, especially since the packaging between the two can be easily mistaken (both say Castrol syntec) and the fact that op's car is using oil at 5w.

a 0w might help solve his problem as he needs an oil for colder climates.