///MDex

OK, I know its almost Feb, but was curious.

Check out the shot below. Seems like the GS400 would qualify as "hot running, heavily loaded, high tech import cars"

OK, they don't run hot, but its gets pretty hot here during the summer

And "guarding against wear during hard driving"

Gee, none of us here drive our cars hard.

Now, this is 15W-50 (currently 5W-30), so I'm guessing those of us in the South would be the only ones considering this oil during the summer.

Oh yeah, I'd use thier M1 filter too. I use it now.

Your .02?

///MDex

Whoops - here the pic

bitkahuna

iTrader: (20)

I would not deviate from what Lexus recommends. I've never heard of a major engine defect on the Lexus V8 so I wouldn't screw with different oil. Lexus doesn't recommend synthetic oil either, just regular (5K) oil changes.

///MDex

True, but Lexus probably never intended some of us adding TCs, Intakes, and launching like rockets with 18s to 20s all the way around either.

OK, so those won't contribute to a major engine defect, but I like to think of taking better care of my GS than what the factory recommends.

A little added insurance, eh?

Come on now, Bit. In HOTlanta? Could it hurt?

In my previous cars, I've always run heavier weights during the summer, and lighter in the winter. Silly? Maybe. But I like knowing I may be adding to the performance or wellness of the engine. Afterall, the oil is the lifeblood right?

Mean Gene

Dex - Unless U get the supercharger, I still wouldn't classify the GS as a "high reving, hot running" import. The intake & exhaust will let a little more air in & out ( an engine's just an air pump ) but it still not a dramatic increase. FWIW, Lingenfelter specified the 5W-30 on my 406 TPI motor until I added nitrous & then he suggested that I consider the 15W-50 ( all M1 lubricants ). Still, Reeves Callaway used 5W-30 Mobil 1 as factory fill in his Twin Turbo Corvettes that Chevy offered back in the late 80's. Reckon 15W-50 won't hurt but I run the 5W-30 year round & it's much hotter ( & humid!! ) down here in Cajunland!:eek:

bitkahuna

iTrader: (20)

It may be bad insurance though. A heavier weight may actually be not as good in starting the engine from cold (overnight, for example). Probably not significant, but again, I think you'll find the Lexus V8 has been THRASHED MERCILESSLY by Lexus themselves in testing a long time ago to make sure it's a TANK, to keep their reliability reputation. Frankly, I think the chance of us breaking it is extremely small. Now the tranny's a different issue, especially with a TC. 'csr' on here destroyed his ($6500 - ouch). But hopefully you took care of that with the cooler.

As an aside - my father-in-law invented Mobil-1.

Shinchan

Hey Bit,

Every dealership uses diff oil. There are not standard brand Oil that the Dealership put in the car. Not use synthetic oil? Just dealership want to make max profit and use the regular oil at the price of regular syn oil. my .02 of thought.

///MDex

OK guys - thanks for the feedback. I thought the 15w50 sounded like the thickness of tar, but a concept to consider anyways.

I like overkill, but I know it can do damage sometimes too.

Bit: really? kick butt! You pester him with questions? Bring him to the dragstrip! I will.

Mr Johnson

I've been considering using switching to Royal Purple this summer. I've been a Mobil-1 fan since my Typhoon days but this sounds like it is worth a try.

Bit: No crap?!? That is pretty cool. Was it a eureka sort of thing or did they plan to develop it?

Peter

zushwa

I know Mean Gene has commented on Royal Purple before. I'm sure he has some good input on it. Here's the place I got my brake fluid from and I think this is a pretty good price for the oil. My experience with them was very good.

http://www.ritegear.com/Royal%20Purple/royal_purple.htm

bitkahuna

iTrader: (20)

Mobil spent tons on research decades ago and pioneered a lot of the synthetic lubricant breakthroughs. My father-in-law has a couple of hundred patents. Too bad they didn't give him a nickel for each can sold . But car oil is just the tip of the iceberg. Greases are a big part of it too. Think about really high stress situations like power station bearings which you DON'T want to re-grease too often! Or the space shuttle 'arm' that gets alternately frozen and roasted in space.

It's a big business...

RON430

Dexter - If I remember right, on a multiweight, the lower number is the viscosity index when cold and the higher number is the viscosity number hot. When you get hot, a higher viscosity oil isn't really thicker. If you used a straight weight, the visosity would markedly thin at higher temperatures. Most of the multiweights are designed to maintain the low temperature viscosity over the whole operating temperature range, which is what the multiweight is all about. This is a real simplification as there are many other important properties for oil that I am sure Mean Gene will probably chip in on. As oils improved, tolerances in engines tightened because adequate lubrication could still be provided by thinner films. In addition, lower viscosities help with gas mileage by reducing some parasitic losses. Low cold viscosity helps the oil run around on startup but I wouldn't figure the difference between 5W and 15W is going to make a big difference on startup (you are not seeing the 50W cold). Also wouldn't figure the higher weight does much. Racing is very different than any street events. In the early days of Trans Am we ran straight 70W Kendall GT1 to try and keep all the oil from collecting in the valve covers whether dry sump or not. That one was very noticeably thicker at room temperature (because it was a straight weight) and we not only were pretty careful on startup but also had to be careful on getting to operating temperature although that never goes away in a race car. The biggest advantage of the synthetics is that superior lubricity at elevated temperatures so as long as you are paying for the synthetic, I wouldn't actually figure the viscosity is making too much difference. But like everyone including me, it seems to make me feel better if I am involved in things like the viscosity of the oil in winter versus summer. In reality, using high grade synthetic, a good filter, and frequent changes (not meant to start the flames from those of you who are convinced that oil changes are wasted money) very likely are more important than the tweaking with weight.

///MDex

Thanks for the detailed feedback Ron.

I was going to mention about the Pour Rate of these synthetics when it is cold (like -65*) so cold starts aren't really anything to worry about, but I know what Bit was trying to say <cough> Dexter is Type A <cough>

I agree with your statements.

Mean Gene

Guyz - Ya'll HAVE been listening to me after all!! Can't add much to what Ron said w/o getting into the technobabble engineering speak but not much more to be said. Auto manaufacturers went to the "thinner" 5W-30 recommendations in an effort to meet the EPA standards when Big brother decided to step in & regulate minimium mpg standards. The tighter tolerances coupled with the lighter oil meant less froctional losses within the engine so mpg went up marginally ( but every little bit helps when you're dealing with the federal government ).
Dex - Actually, U'd be wise to consider an oil's pour point. It's been proven that 80-85% of an engine's wear occurs in the first few seconds of running ( especially the morning's first start as the oil's still in the crankcase & there's no oil pressure for a few seconds until the pump gets it moving ). Obviously the sooner U can get the oil flowing the better. Syns do this & I have firsthand ( although not scientific ) experience with this. My Corvette had the digital gauge package & came with the standard Mr. Goodwrench ( Mobil non-syn ) 5W-30 factory fill oil. I noticed that it took 3-4 seconds in the morning for the oil pressure gauge to register anything ( during the winter - roughly only low 40's in Louisiana ). I reached 5k miles & changed to 5W-30 M1 synthetic & found that I had oil pressure within 1-2 seconds of the cold start! That, as well as my offshore experience with synthetics sold me on their benefits far outweighing their cost & I haven't looked back since.
In the last 2 SAE sponsored tests, Royal Purple has finished at the top. We're even using it in some of our more critical pieces of rotating equipment ( multi-million dollar compressors ) but it's cost keeps us ( & me ) from running it exclusively. That's it's only downside as far as I'm concerned. For my current situation ( being naturally aspirated & non-nitrous ) M1's just fine. However, I'd probably move up to RP IF I had forced induction just for piece of mind. Might be able to work out a group buy deal from my RP vendor - we just sent him & his wife to Hawaii because of the amount of lubricants we've purchased from him!!:eek: At least he sent me some NASCAR tickets for Atlanta this year!

Mr Johnson

Mean Gene: Count me in on that RP group buy!