540 RAT

So, I went to Pep Boys in Southern California last weekend on Feb 15, ’09 to see if they had the new Castrol Edge motor oil, how they positioned it marketing-wise, and what the price was. They had plenty of it on hand, in the two viscosities currently available, 5W30 and 10W30. The price and how it compares to some others:

Royal Purple 5W30 (full syn) $8.99 per quart – street oil, not their XPR Racing Oil

Castrol Edge 5W30 (full syn) $7.99

Castrol Syntec 5W30 (full syn) $6.99

Castrol GTX 5W30 (dino) $3.99

As you can see, Castrol has positioned their new state-of-the-art, top-of-the-line Edge, right between Royal Purple and their previous top-of-the-line Syntec. They refer to Edge as an Advanced Synthetic, while they call their older Syntec, a std synthetic.

While Edge motor oil isn’t exactly cheap, it could be considered a slight bargain when compared to Royal Purple, when you consider it has more approval ratings than Royal Purple, and the tests Castrol refers to, says that even Royal Purple did not provide better wear protection. And that is saying something, considering that Royal Purple previously had no equal in terms of wear protection.

GM’s “GM4718M” oil spec:
It is interesting that Castrol Syntec 5W30 used to carry the GM4718M rating, but then maybe a year or so ago, it lost that rating. And Royal Purple 5W30 also used to carry that rating, but while I was at Pep Boys, I noticed that that rating has also dropped off Royal Purple as well. What’s up with that? But the new Edge HAS the GM4718M rating, so for those folks who want to use what GM calls for in their ride, you can find it there.

I picked-up some Edge, so I’ll give it a try the next time an oil change is due in one of my late model cars. But even though Edge tests show that it has very impressive wear protection properties, which means it could even be considered for flat tappet motors, I’m planning to stay with Royal Purple XPR Racing Oil in my 540 Monster Motor. That particular oil still has no equal, but then you REALLY have to pay for it.

Young69Owner

I use Royal Purple 5W-30. If I don't mind the cost, can I switch to their racing oil on a daily driven car? Will it yield any pros/cons? Free up some power?

Jeff_Keryk

I believe race formulated oils do not have the proper detergent properties needed for street cars.

540 RAT

Yes, Royal Purple XPR Racing Oil is perfectly suitable for daily driver usage. Because it has plenty of TBN (10.9) to deal with acidity concerns, as well as plenty of magnesium (10 ppm) and plenty of calcium (3039 ppm) which are both detergent/dispersants, in the 5W30 XPR that I had lab tested, it even works just fine using normal oil change intervals. And will keep your engine safe and squeaky clean inside. In addition, no oil has a better ability to prevent wear. Because it reduces friction so well, it may certainly free up some hp over the oil you use now, though its unlikely that you'd feel it in the seat of your pants. As a comparison, Valvoline has said that their NSL Racing Oil requires changing at 500 mile intervals. The only thing about using Royal Purple XPR oil in a daily driver is that it contains high levels of zinc (1421 ppm) and phos (1338 ppm), so it would not be suitable for long term use in newer cat equiped cars. Otherwise, go for it, only your wallet will hold you back. Last time I checked, it was a whopping $14.00 a quart, so if you drive a lot and change oil a lot, that can add up real fast.

Young69Owner

Do I need to worry about the viscosity (was it 20W-50?) I was changing my oil every 8K or so miles and I looked at my last batch and it had no particulate whatsoever in it. Is 8K miles okay for the racing stuff?

540 RAT

The best viscosity to use, is the thinnest oil that will still provide reasonable HOT oil pressure.

Some premium synthetics do claim extended change interval capability. The oil itself may still be functioning acceptably with a lot of miles on it, but that's NOT the whole story. Those oil makers hype that just to offset their higher cost. And they hope that people will still buy their oil, if they can spend the big bucks less often. If their syn oil costs twice as much as dino, but needs changed half as often, then there is no additional cost to running the high dollar synthetics. That's their story and they're sticking to it. The problem is, they leave out an important aspect to doing that. And that aspect is CONTAMINATION. No matter how good the oil is, and no matter how good the oil filter is, the oil still becomes contaminated as the miles add up.

Everyone will have their own opinion about change intervals, but to me, I think it is unwise to go beyond a 5,000 mile change interval in a daily driver. And of course all the Jiffy-Lube type places will say you need to change it every 3,000 miles. But of course they are just trying to make money off of you. Personally I change oil in all my daily driver cars at 5,000 miles. I use premium oil and premium oil filters, and yet at that time, the oil is always extremely dark, some might even say nearly black, so to speak. That of course, is what you should see if the oil is doing its job. You want that contamination (which flows right through your filter) suspended in your oil, not all stuck all over your engine's internals. And that contamination is more than enough reason to change your oil at reasonable intervals. I'd never go beyond 5,000 miles no matter what the oil or the oil filter. And I'd never recommend anyone else go longer than that either.

Don't forget, it cost Toyota millions of dollars from failed engines in Toyota's and Lexus', due to sludge formation. And that whole problem was traced to the ridiculously high oil change intervals they recommended.

I think if people want to use high dollar oil, they should accept the fact that it will simply cost more to get the extra capability that oil can provide.

Young69Owner

That's great info, can the racing oil go for 5,000 miles and is it available in a 5W-30? That's what I was told to use and I have minimal oil knowledge as you can tell.

540 RAT

Yes the Royal Purple XPR Racing Oil comes in 5W30, that's what I have myself. And yes 5,000 miles on it would be fine. It isn't easy to find in person, so I order mine from Summit. But of course its not for the faint of wallet.

Young69Owner

Thanks, undstood. If I start to have cash flow issues, I'll go back to their street oil.

Young69Owner

One more question -

I've been using that Lucas Oil Treatment (one quart per oil change). Is it doing anything for me? Is it hurting the lubrication of the 4 quarts of Royal Purple? I do not have a high mileage engine yet, but I'm working on it a little every day. When I switch to the racing oil, should I just go 5 quarts of that? Thanks, again!

540 RAT

DO NOT use that Lucas Oil Treatment. You are wrecking the Royal Purple when you do that. Some testing has shown that Lucas Oil Treatment causes foaming and can do more harm than good. Any good quality motor oil is only made worse by putting in additives. They already have everything in them that they need to do the job they are designed to do. But of course there are different motors oils available for different needs. Just choose the right one for your application and you are good to go, with no additional additives. Royal Purple XPR Racing Oil is the best motor oil on the market, period. Use it straight as it comes out of the bottle. If you do anything to it, you will make it worse.

Young69Owner

Thank you!!! I had been listening to the blonde that used to work at AutoZone. I guess she knew more about looking really good than oil...

jb78L-82

I am just curious how you feel about Mobil 1 15W-50 for flat tappet cam engines? I have been using it in my L-82 since 1985 and only use 15W-50 since it has 1,200 PPM of ZDDP now. I am thinking of trying Mobil 1's new 0W-30 Racing oil since it has 1,750 PPM of ZDDP. I used to run Mobil 1 5W-30 until the EPA mandated the ZDDP change for ALL mass marketed oils including Diesel Oils like Shell's Rotella T. I pay $25 for 5 Qts of Mobil 1 15W-50 at Walmart. You really cannot beat that price for a true synthetic.

Lastly, I suspect that Castrols new Edge is a Group IV synthetic and the regular Syntec is a group III (which i know it is). Royal Pruple and Amsoil, I believe, are also Group IV's. I think Castrol is trying to catch up at this point.

http://www.mobiloil.com/USA-English/...ing_0W-30.aspx