Why?
Indeed, one reason that prompted me to take on a little extra work. My concern was not with the engine oil, rather the gear oil. It is supposed to be GL-4 & GL-5. Being GL-5 it in theory shouldn’t be used where there is yellow metal. However Royal Purple was claiming it was safe for use in transmissions with brass blocking gears.
A couple of us Audi guys with very expensive transmissions didn’t want to go on marketing hype. After cornering a Royal Purple rep at SEMA and many, many phone calls they finally admitted it probably shouldn’t be used in a transmission, or at least they thought maybe it wouldn’t be a good idea. There words were something to the effect of, we don’t really know Audi transmissions, so maybe you don’t want to use it.
Of course I had just flushed and filled one of my spare boxes with it just a month ago. I hadn’t run that set of gears yet, and thankfully so. I’m going to drain and flush it as soon as I get some more oil in stock. I ran out of what I normally carry, so I have to restock.
More details to follow.
Castrol TWS 10W60
Shelby charger -royal purple 10w40
Daytona turbo- Mobil1 10w30
SRT4 -mobil 1 5w30
Saturn vue- name brand conventional 5w20
Jetta- whatever’s on sale 10w30
RX7- Amsoil 20w50
Redline 5-30. It’s closing in on $10/quart. But I only change it every 10k.
I love how people will throw “whatever’s cheap” into their daily drivers that get exposed to more miles, harsher conditions, and are generally required to be reliable…
while putting $50 oil into the car that may see 3k miles a year and only on sunny days.
10w60
im sorta hesitant to use 20w50 that my builder recommends, my turbo feed lines arent all that wide
240- royal purple 5-30 $5.18qt 
civic- used oil from any shop (freeeeeee!!) hahahha hondas dont need oil.
I typically don’t keep cars long enough to change the oil.
I never changed the oil in the Evo.
j/k
5w30 or 10w30 mobil one
truth.com i’ve had ELF syn in the Trans Am 0w-30 and Mobil 1 5w-30. But then again i drive the bird about 8k in summer. Haven’t changed the shadance’s yet but she’ll get some penz and a delco filter.
The DD has been reliable for over 135k miles on bargain oil, only making 90whp has its advantages. I do put more expensive oil in the car that makes over 4.5 times that amount of power with the hope that it will buy my finicky little rotary a few more thousand miles over its already short lifespan.
2003 Crown Victoria,6 qt’s Mobil 1 or Penn 5w20.
1994 Caprice,5 qt’s Penn 5w30.
No Fram oil filters,i use anything but…
i use mobil clean 5000 oil and a AC Delco pf47 on everything i have in my driveway
i let it go to atleast 4k before i change it on the 05 blazer and my mom’s 03 impala
i wait for the oil life to get down to about 25% on my dad’s 05 malibu
and on my 01 S10, i use 3.5q and 1q of lucas stabilizer because it stopped the rear main from leaking! if that motor ever dies, the truck gets the LSx swapped in finally
Mobil 1 full synthetic 10w 30 with a Mobil 1 filter in the Mustang every 1500 miles
Penzoil or Valvoline 5w 30 with a Hastings filter (Wix filter with a different name slapped on it) in the Jeep ever 2500-3000 miles
Redline 10w30.
civic - Amsoil 20w50
sti - Amsoil 10w-30
Whatever monroe muffler puts in.
Daily driver: 5W/30, any name brand will do. Change per oil life monitor (~7,000m)
Camaro: Brad Penn 10W-30 partial synthetic. ~3,000m changes.
Race car: Brad Penn 20W-50 partial synthetic. New oil at beginning and mid-season (~30 passes).