5W20 or 5W30

[rickshaw]

Newbie here ready to change the oil in my 02, that has 50K miles and the previous owner did the quick lube method of cheap oil.

I'm a synthetic guy and wonder how much difference there is between the different oil viscocities. Anybody using 5w30? It's plenty warm in FL do that should not be a problem.

And any thoughts on a flush before the change?

 

[SVT32VDOHC]

Use what the sticker under the hood recommends. Don't play around with different weights with MOD motors.

Don't flush the motor either. That just takes any crap inside and puts it somehwere else...like your oil pump...then your motor could go bad.

 

[evil281]

i use 5w30 and my car runs great

 

[rickshaw]

thanks for the feedback. i accidently used a different weight in my truck and the oil pressure went very high at WOT.

the reason i asked was Costco is selling a Mobile 1 6 pack of 5w30 for $35.00. OK, so I'm cheap.

 

[ThunderHorse]

My owners manual says to use motorcraft 5w20 full synthetic. However I use the Mobil 1 5w20 because there is no difference to me and mobil 1 is easier to get where I live. I have used 5w30 mobil 1 in the past and had no problems with it.

 

[SVT32VDOHC]

99-00 Mustang GT's ask for 5w30. 01-04 Mustang GT's ask for 5W20.

Waaaaay back in the day, there was a thread here or somewhere else about a guy with a 99 Cobra/01 Cobra who used 10w30 in the car because he was "hard" on it. Well the dealer proved it starved the heads from oil and proved the oil was in fact 10w30. They voided his warrenty.

Since then, I use what Ford says.

 

[Gearbanger 101]

99-00 Mustang GT's ask for 5w30. 01-04 Mustang GT's ask for 5W20.

And the best part about it is, is there's not a damn bit of difference in the tolerances of the engines. In all honesty, Ford probably went with the 5W20 synthetic because they likely buy it cheaper in bulk....and putting the word synthetic in front of it allowed them to move oil change intervals from 5,000km to 8,000-10,000km between changes.

Waaaaay back in the day, there was a thread here or somewhere else about a guy with a 99 Cobra/01 Cobra who used 10w30 in the car because he was "hard" on it. Well the dealer proved it starved the heads from oil and proved the oil was in fact 10w30. They voided his warrenty.

Since then, I use what Ford says.

I would love to see how they "proved" that. My guess is that they fed him whatever they thought he needed to hear in order to not have to cover the warranty claim. After working for a Dealership for 4-years, I can tell you first hand they'll try whatever they can to get out of warranty work.

As far as oil goes....I stick with 5W30 in mine....dino...synthetic...its all the same. If I run synthetic in it, I wait a little longer between changes. Then again, I don't seem to fill my oil separator as often with the dino oil, so that's what I've been sticking with. Not to mention with the dino oil you change your filter twice in 10,000km, where with the synthetic oil you're more likely to only change it one. And in the end....its the quality and condition of your oil filter that’s the most important....not the type of oil you're running.

 

[tag4car]

^ i remember hearing something about the CAFE rating

 

[SVT32VDOHC]

And the best part about it is, is there's not a damn bit of difference in the tolerances of the engines. In all honesty, Ford probably went with the 5W20 synthetic because they likely buy it cheaper in bulk....and putting the word synthetic in front of it allowed them to move oil change intervals from 5,000km to 8,000-10,000km between changes.

I would love to see how they "proved" that. My guess is that they fed him whatever they thought he needed to hear in order to not have to cover the warranty claim. After working for a Dealership for 4-years, I can tell you first hand they'll try whatever they can to get out of warranty work.

As far as oil goes....I stick with 5W30 in mine....dino...synthetic...its all the same. If I run synthetic in it, I wait a little longer between changes. Then again, I don't seem to fill my oil separator as often with the dino oil, so that's what I've been sticking with. Not to mention with the dino oil you change your filter twice in 10,000km, where with the synthetic oil you're more likely to only change it one. And in the end....its the quality and condition of your oil filter that’s the most important....not the type of oil you're running.

I agree. The dealer will do whatever they can to get money. I just remember the thread. Here at work, we put whatever oil is on sale in your trucks..lol. We never have problems.

As far as my Mustangs though. I put what is recommended.

96 Cobra...(even with the Vortech) gets conventional 5w30. No synthetic for me.

04 Cobra...haven't done an oil change yet since I just bought it. It will get the required 5w20. Don't know if I'll go with synthetic yet. It has 5,700 miles. If I do go synthetic, it is going to be Ford Motorcraft brand. That is a blend. I used that in my 04 F150 lease truck and it seemed fine.

 

[mrvax]

If I'm not mistaken, there was no engine change between 99 & 00 when the viscosity changed. I believe the thinner oil got a wee bit better gas mileage.

So, if you have a warantee, go with the "official" brand for your year.
No warantee? Then use the 5w-30 that was designed for use in the mod motor.

BTW: When my Mustang hit 100,000 miles I switched to full synthetic. I could tell a difference.