10W-30 Motor Oil okay to use (in California)?

[Seraphitia102]

My dad has 5 quarts of Mobil 1 10W-30 oil lying around the house. The car that it was meant to be put in died so I want to use up his oil.

I know 10W-30 is thicker than the recommended 5W grade but since I live in California (where it's never cold), would using the slightly thicker viscosity be a problem?

I used 10W-30 in my old Toyota minivan without a problem even though it recommended 5W-30. Though I'm sure Mustang engines can possibly be different.

 

[Kilgore Trout]

I wouldn't do it personally. The first number is the viscosity when cold and when the engine is cold is when it needs lubrication the most.

I am sure a lot of smart pro mechanics will correct me but I would not risk it to save $20 on five quarts of correct oil.

 

[trinity_gt]

And to counter, I'd say it'd be fine. 5W20 is a mileage oil: Low viscosity means few pumping losses and higher efficiency. Ford's own GT500 engine uses 5W50 motor oil. At its core, it's a mod motor like all the rest.

10W30 is, really, quite close to 5W20: It's not like the OP wants to pour 75W140 gear oil or something...

 

[streethorse]

No problem at all. You could put 3 qts of 5w20 and 3 qts of 10w30.
Doesnt hurt any thing to mix weights.

 

[Greenscobie86]

I've ran 10w-30 Dino oil as well as Motorcraft 5w-30/5w-20 on my car.

My 5.4 Expedition get M1 5-30 or 10w-30, whatever is found cheaper.

No car's experience any problems, other than the mustang which eats less oil(leaky valve seals) if a thicker oil is used.

I'm sure you will be fine. Like soemone above said, you arent putting gear oil in there.

 

[bdcardinal]

you will be fine. the 5w20 is for CAFE only on this application. just for reference in Australia they spec 5w40, and 15w50 on mod motors that are made on the same production line as the ones sold here.

 

[streethorse]

I ran the mobil 1- 15w50 in my 99 for 5k miles once, ran great, made the
engine quieter. It was in the summer (100 degrees +)

 

[Seraphitia102]

I wouldn't do it personally. The first number is the viscosity when cold and when the engine is cold is when it needs lubrication the most.

I am sure a lot of smart pro mechanics will correct me but I would not risk it to save $20 on five quarts of correct oil.

Well, it's not just saving $20 but more like $50 since Mobil 1 runs about $6-7 a quart. d:

And to counter, I'd say it'd be fine. 5W20 is a mileage oil: Low viscosity means few pumping losses and higher efficiency. Ford's own GT500 engine uses 5W50 motor oil. At its core, it's a mod motor like all the rest.

10W30 is, really, quite close to 5W20: It's not like the OP wants to pour 75W140 gear oil or something...

what's OP? As for gear oil, I think I have 75W90 in my differential. Since 5W-20 is a mileage oil, do you have any gains in any segment using oil that's not "energy conserving?"

No problem at all. You could put 3 qts of 5w20 and 3 qts of 10w30.
Doesnt hurt any thing to mix weights.

Weird. I never heard of mixing weights. Does mixing 5W-20 and 10W-30 get 7W-25?

I've ran 10w-30 Dino oil as well as Motorcraft 5w-30/5w-20 on my car.

My 5.4 Expedition get M1 5-30 or 10w-30, whatever is found cheaper.

No car's experience any problems, other than the mustang which eats less oil(leaky valve seals) if a thicker oil is used.

I'm sure you will be fine. Like soemone above said, you arent putting gear oil in there.

In reference to gear oil, is it because it's hella thick (140)? I'm relieved to hear that you ran multiple weights of oil without any problems.

you will be fine. the 5w20 is for CAFE only on this application. just for reference in Australia they spec 5w40, and 15w50 on mod motors that are made on the same production line as the ones sold here.

I always love your posts, don't quite know why As I answered above, are there any benefits to using a oil that's not tilted towards CAFE ratings?

I ran the mobil 1- 15w50 in my 99 for 5k miles once, ran great, made the
engine quieter. It was in the summer (100 degrees +)

dang that's a pretty heavy weight. what led you to use that weight of oil? I hear many people on the track use that weight oil as well.

 

[streethorse]

I had 110k miles on the car and it was super hot that year, just tried
it to see the difference. Im not really loyal to any brand, weight,
synthetic or conventional. I try something different almost every oil change.

As for mixing weight yes you would get 7w25 by mixing 5w20 and 10w30.
I called the tech lines of Mobil 1 and Valvaline and they say its fine to mix weights.
I also mix conventional and synthetic as long as its the same brand of oil.

Right now Im running 5 qts of mobil 1 5w20 with 1 qt of Mobil clean 5000 10w30 conventional.
I had the 1 qt left over from the last oil change which was 6qts of mobil clean 5000.

 

[Kilgore Trout]

Can I change my answer to "it will be fine"?

 

[Seraphitia102]

I had 110k miles on the car and it was super hot that year, just tried
it to see the difference. Im not really loyal to any brand, weight,
synthetic or conventional. I try something different almost every oil change.

As for mixing weight yes you would get 7w25 by mixing 5w20 and 10w30.
I called the tech lines of Mobil 1 and Valvaline and they say its fine to mix weights.
I also mix conventional and synthetic as long as its the same brand of oil.

Right now Im running 5 qts of mobil 1 5w20 with 1 qt of Mobil clean 5000 10w30 conventional.
I had the 1 qt left over from the last oil change which was 6qts of mobil clean 5000.

How does your car take 6 quarts of oil?

Can I change my answer to "it will be fine"?

No, but you can edit your answer above

 

[streethorse]

Yeah it takes 6 qts to fill. My 99 only took 5.5 qts. Its normal.

 

[joshjwc9]

Or just go to WalMart and explain that your father bought you the wrong oil weight!?

If they aren't opened Wally World will just put them on the shelf again anyways!

 

[bdcardinal]

If they aren't opened Wally World will just put them on the shelf again anyways!

i have seen open bottles with used oil on the shelf at WalMart.

btw fwiw BMW uses 10w60 in their M5 and M6 V10's, little higher level of performance than a 4.6L.

i have used 5w20, 5w30, 0w30 and 10w30 in all different brands, non synthetic, semi synthetic and full synthetic, in my mom's Grand Marquis and guess what, yup fine no issues with the motor whatsoever. and it usually gets changed every 5,000 miles. my 98 GT mostly saw Mobil 1 5w30 including hard track days, no issues whatsoever.

on a unrelated note, my Volvo gets German Castrol 0w30. i change it every 7500 miles per the manual, the car sees max boost, 14.7psi, multiple times a day, again no issues whatsoever.

 

[CobraRed_96_GT]

A lot of 4.6's use 6qrt - i put just over 6qrts in. Pan is fine up to 7 for running (for mustangs calling for 6qrts).

As for weight, i've been using Mobil 1 10W-30 for the last 2 years. It's fine. I used to work for an oil manufacturing company - the differences between two company's 5W-30 can be more drastic than the same companies 5W-30 vs 10W-30

 

[Kilgore Trout]

Well, it's not just saving $20 but more like $50 since Mobil 1 runs about $6-7 a quart.

Actually AutoZone is running a sale until Sept 9th where you get 5 quarts of Mobil1 EP and a oil filter for $19.99

 

[Seraphitia102]

WHOA really?????? hehe i love shopping. heading there on Saturday

 

[DropTopPony]

My car has only ever had 10W30 in it. I'm pretty sure thats what came in it from Ford then they changed to 5W30 a few years later.