Absolutely... Synthetic oils use higher quality friction modifiers to make the oil more slippery and stronger than conventional oils... This allows the engine to run easier and smoother,,, increasing gas mileage...

How is synthetic motor oil different from regular (conventional) motor oil???

Synthetic engine oil products are produced through a synthesis process that takes very small molecules and assembles them into larger designer molecules with premium lubricating properties...

Others may be produced through a synthesis process that takes very large molecules, breaks them apart, and re-arranges them to produce designer molecules with premium lubricating properties...

In either case, the end products are base fluids with extremely good lubricating properties...

Conventional base stocks are refined from crude oil through various hydrorefined/hydrotreated refining processes to separate and/or convert undesirable compounds to yield a suitable finished base stock.

So I have read... Midnight here and I am researching Oil,,, Man I need a life...
Please don't ask about Tranny Fluids...


Wish there was a Chunnel/Tube from here to France I'd join Ya for the Rally we could make that FUN...
Start Digging...

 

Hey Randy, the reason I made that statement is that I had Castrol GTX in the car and when I swithed to the royal purple my engine got noticeably quieter. Whether or not its better I can't say, it's just what I noticed. I also switched over to it in my wifes charger and it also made a difference as far as engine noise goes.

 

Count;

No reason not to come any way.

Sure we can find you a car to drive or bungee cord you to the back of something.

Of course the PBTW gets a seat, don't forget her.

Hey I don't know if you have seen his posts but look up this kid on the forum: Josh850


oh that's big.....sorry.

Anyway get in touch with him please, he is looking for a cheap 'Starter Jag' and is in your Dominion....you are the Count of Florida right?

I am serious about coming for the Rally.

There are actually a couple of guys renting classic Jaguars in the UK and lot's of folks take them on jaunts over the Channel......don't make me send this to the PBTW or she will come without you when she hears about the Chateaus in the Loire valley.

cheers and thanks,

jj

 

I continue to be fascinated with the human mind. In an almost strange Pavlov kind of way, it draws intangible technical conclusions that have a strong correlation to cost. This is consistent with those who spend premium money for items like filters, fuel, oil, tires, etc. Not being educated as a psychiatrist, hell, it took two tries just to get my GED, I'll bet this has something to do with justifying the added expense or maybe buyer's remorse. If nothing else, it proves the strongest force in the universe is a good marketing campaign.

 

Looks like we are about to see why most of the guys who have been on this forum for a while stay out of the never ending "what type of oil and when to change it" discussions that pop up from time to time.

It always seems to evolve into something of a bloodbath and then the mods shut it down.

 

Hopefully not this time, healthy and calm discussion seems to have prevailed so far. I think pancake bunny stands at the ready to intercede if need be.

 

Most manufacturers of cars with turbochargers specify synthetic oil for those cars. I own a Saab 9-3 turbo, and it's owner's manual specifically says that synthetic oil is REQUIRED. I don't know the technical details behind why they require synthetic oil, but there is apparently something about the synthetic oil that the turbocharger requires. For me, it's worth an extra $10 every 10,000 miles to have a little bit of peace-of-mind. The price difference between synthetic and non-synthetic is very small these days. It costs an extra ten cents every hundred miles or thirty cents per fill-up to use synthetic.

 

I can take a stab at that one Rev, as it relates directly to my former career in the gas turbine field. I knew that working there for over 30 years would come in handy some day.

Both turbos and gas turbines (jet engines) share the common design characteristic of having high speed bearings located in very close proximity to the drive turbine sections. These components run at extremely high temps, well beyond the flash/smoking/coking temps of conventional oils. This does not pose a problem when the engine is running, as the oil is circulated quickly enough through the cavity as to not reach the 'overheat' temp prior to being cooled and reused. The problem comes after engine/turbo shutdown where heat soak back raises the bearing cavity and residual oil temp beyond it's maximum allowable temperature. The coked oil would soon clog the bearing cavities and restrict oil flow, leading to bearing failure. Synthetic oils have adequate temperature margin to avoid this issue, hence their requirement.

The sort of temps required for all of this to happen do not occur outside of the turbo assembly on almost all piston engines- our Jags included.

Hope this helps.

 

My bad I guess for trying to help a fellow member. I haven't posted in a while for exactly these type of reasons. I wasn't suggesting he use RP I was just giving my opinion. And the reason I switched wasn't because of the cost. It was from research on this site when, you know, forget it, my bad.

 

Dpez;

You can't listen to the critics...Like my Daddy used to say "If we did that we would all be smoking cigars and wearing girdles."

cheers,

jj

 

How about bringing some science to this discussion?

Came across this article that may be informative.

Oils Against Oils - Major Oil Brands go head-to-head on the dyno.

cheers,

jj


Oils Against Oils
A Shootout of a different kind: major oil brands go head-to-head on the dyno and in the lab.
What do you know about oil in your car's engine? From the ads, you're led to believe the most exotic part of a Ferrari's engine is in the sump, "oils aint oils", "you know what I mean", one brand is the "world's most advanced" and "the best protection you engine can get" for every John, Dick and Barry.

The basic concept of oil is to provide a film of lubrication between two surfaces, reducing friction, wear and heat and ensuring an engine's long life span. But the reality is that while all claim to be superior, there are some that are better than others. We decided to test most of the major brands to see how the well-known brands, the ones most of us can readily buy, shape up in a real-life engine test.


COME's in-house engine dynamemeter was the venue for all our testing. TEST PROCEDURE
The idea behind the test was to run each oil through a short yet grueling dynamometer session measuring various parameters including horsepower, followed by professional oil analysis.

Aiding our quest was COME Racing's Sam Blumenstein who offered his hi-tech SuperFlow engine dynamometer. Sam literally put all his time and equipment on the line as he was extremely interested in seeing the results. The engine was mildly-modified five-liter V8 for tow main reasons: COME's dyno is designed to quickly and easily accept this type of engine and FF&R's sister publication, Performance Street Car, would be running the same story.
Next in line was Bill Reid of Lubrication Management who offered his oil analysis abilities - an intricate operation requiring considerable expertise and equipment. The benefit of oil analysis for the average consumer, fleet owner or engine builder is the results will indicate what engine internals are wearing, to what extent they are wearing, how the oil affects wear, if the oil is contaminated with fuel, general discolouration, viscosity losses and more.

We also called upon Ryco, which kindly supplied us with all the oil filters we needed for accurate testing.

We decided to only run high-quality synthetic oils because not only do they represent a brand's top oil, it's the oil most relevant to performance enthusiasts. We would also establish a base line with a mineral oil. Each oil would be subjected to three timed sessions at high engine loads, between which would be three full-power runs.

The intent was to establish a number of criteria. First, whether any of the oils would improve horsepower, whether any of the products would lose viscosity, evaluate its ability (or lack thereof) to prematurely wear components or suffer from discolouration. As it turned out, discolouration didn't prove to be a factor.

A neat technical tip is, when possible, always fill new oil filters with oil to prevent starvation on start-up, since oil travels from teh sump, to the filter then the engine's parts. we marked filters to eliminate any potential confusion and the sump probe logged oil temperatures. To properly execute an oil analysis oils are run in extreme conditions for at least 70 hours, but given its complete impracticality, we hoped the much shorter testing would provide at least measurable results.

We approached 10 oil suppliers/manufactures, informed them of our intention, and all were reasonably keen and eager to be involved, although Pennzoil didn't want to commit and Penrite flat out said no - a little strange given this company has actually advertised with and for this market.
VISCOSITY
Viscosity is the measure of the resistance of a liquid to flow. The thicker the oil, the higher the viscosity. Lubricating oils are usually measured in SAE grades ranging from 0 SAE for a very thin oil to an extremely thick 140 SAE - a grade normally seen in slow-moving industrial applications.
An oil's viscosity number relates to its cold and hot temperature viscosities: a 0W-30 oil is very thin when cold, and of average viscosity when hot, whereas a 20W-50 oil is thick when cold and can cope better with much higher temperatures.

A car engine requires oil capable of flowing at low temperatures to lubricate internal moving parts on start up, and it must retain enough film strength (thickness) to protect surfaces as temperatures rise.

Generally, an old-tech engine like a push-rod V8 has larger tolerances than a high-tech twin-cam four-cylinder, so anything thinner than around SAE20 may provide too-little protection for start-up.
With tighter-tolerance engines, a 0W-30, 10W-30 or maybe a 10W-40 is more appropriate and a 20W-50 may be too thick. Check the owner's manual for the recommended oil viscosity for your car.

Strangely, although we specified exactly which type of engine we were using, and that its recommended rating is 20W-50, some companies sent us SAE viscosities of 0W-30 or 0W-40!
VISCOSITY TEST
Note that being such a short test it was felt that none of the oils would lose any of its viscosity rating, and indeed six oils suffered an inconsequential loss of less than one percent. However the following five suffered significantly.

Under normal conditions, its suggested oil which loses viscosity this quickly would be subject to significant losses over 5000km. Indeed, one would be suspect of the potential for increased wear over this period. Interestingly, in stark contradiction, Hi-Tec actually fared extremely well in the wear particle analysis, where results of the other varied.


Oil Product Viscosity Loss % Type Test# Torco MPZ 18% Synthetic #5 & 6 Shell Helix Ultra 14% Synthetic #8 Shell Helix Plus 12% Petroleum #1 Hi-Tec HTO 8% Synthetic #9 Castrol R 6% Synthetic #12
WEAR PROTECTION
The main function of oil is to lubricate an engine's moving parts to prevent friction and wear. The oil forms a thin film on, around and between parts which work in close proximity. Metal to metal contact creates tremendous heat and frictional forces and causes wear in the form of minute particles of metal, which in either captured and is suspended in the oil, or is trapped in the filter.
A good quality motor oil contains anti-wear additives to protect engines by bonding to metal surfaces and forming a protective layer, for optimum performance for a cold-start. This layer doesn't in fact prevent the parts rubbing together, but minimizes the effects of contact and produces similar and fewer wear particles. Quality synthetic oil will contain the necessary additives to provide the protection needed, generally concealing the need for any aftermarket additives.
The oil filters are carefully opened with a specialised tool which prevents metal pieces being cut off. Then the oil is heated so any particles are suspended rather than tsettled. A probe/magnet is then placed in the oil to collect a sample, careful not to touch the sides of the filter body.

WEAR METAL TEST
Indicates size and number of wear particle for each oil. The higher the rating the greater number and size of wear particles.
Rating Oil Average particle size Overall (micron) Test# #1 Amsoil Series 5-10 micron 5-50 micron 10 #2 Hi-Tec HTO 15-20 micron 10-60 micron 9 #3 BP Visco 5000 15-20 micron 15-60 micron 4 #4 Shell Helix Ultra 15-25 micron 15-60 micron 8 #5 Shell Helix Plus 10-20 micron 15-50 micron 1 #6 Mobil 1 5W-50 20-25 micron 15-60 micron 3 #7 Mobil 1 0W-40 15-20 micron 15-50 micron 11 #8 Castrol R 20-30 micron 15-100 micron 12 #9 Torco 15-20 micron 15-100 micron 5 & 6 #10 Royal Purple 15-20 micron 15-100 micron 7 #11 Castrol SLX 20-25 micron 15-100 micron 2
OIL PROPERTIES
The basic difference between a mineral and petroleum based oil and a full synthetic oil is one is dragged out of the ground while the other is man made. Mineral oils are subject to the impurities associated with petroleum based products, plus they don't have the additives inherent in synthetics. Synthetics on the other hand, by virtue of the fact they're man made, can be equipped from the outset with any number of additives to aid lubrication, reducing potential contamination, slow viscosity losses and as such are generally seen to be a vast improvement over mineral oil.
The oil probe is then placed in a solution to free it of all oil, leaving behind just the raw wear particles. Once the magnet is clean, a piece of cellophane tape is applied to stick any metal particles for analysis either on a contrasting background or under a microscope. TEST RESULTS
#1 SHELL HELIX PLUS 20W-50 MINERAL
RPM 3000 3500 4000 4500 5000
Ft-lb 255 271 300 291 268
HP 145 180 228 249 255
Maximum HP: 256.2 @ 4900rpm
Maximum Torque: 303.1 @ 3900rpm
Oil temp: 187F
Oil pressure: 44-54psi
Water temp: 188F #2 CASTROL SLX 0W-30 SYNTHETIC
RPM 3000 3500 4000 4500 5000
Ft-lb 262 290 301 293 272
HP 149 193 229 251 259
Maximum HP: 263.7 @ 4900rpm
Maximum Torque: 314.2 @ 3750rpm
Oil temp: 175FOil pressure: 43-55psi
Water temp: 186F #3 MOBIL 1 5W-50 SYNTHETIC
RPM 3000 3500 4000 4500 5000
Ft-lb 265 295 305 295 274
HP 155 197 232 252 261
Maximum HP: 261.3 @ 5000rpm
Maximum Torque: 318.1 @ 3700rpm
Oil temp: 197F
Oil pressure: 44-55psi
Water temp: 186F
#4 BP VISCO 5000 5W-40 SYNTHETIC
RPM 3000 3500 4000 4500 5000
Ft-lb 263 286 305 298 271
HP 150 190 232 255 258
Maximum HP: 260.7 @ 4900rpm
Maximum Torque: 317 @ 3960rpm
Oil temp: 194F
Oil pressure: 52psi
Water temp: 187F #5 TORCO MPZ20w-50 SYNTHETIC
RPM 3000 3500 4000 4500 5000
Ft-lb 262 300 304 294 273
HP 150 200 232 252 260
Maximum HP: 260.3 @ 5000rpm
Maximum Torque: 313.9 @ 2700rpm
Oil temp: 200F
Oil pressure: 52psi
Water temp: 191F #7 ROYAL PURPLE 21 SYNTHETIC (no SAE
rating - analysis suggests around 0W-30)
RPM 3000 3500 4000 4500 5000
Ft-lb 265 307 304 301 279
HP 151 205 231 257 266
Maximum HP: 266.6 @ 5000rpm
Maximum Torque: 314.9 @ 3750rpm
Oil temp: 200F
Oil pressure: 52psi
Water temp: 190F #8 SHELL HELIX ULTRA 15W-50 SYNTHETIC
RPM 3000 3500 4000 4500 5000
Ft-lb 274 300 301 299 273
HP 157 202 229 256 260
Maximum HP: 260.7 @ 5000rpm
Maximum Torque: 309.2 @ 3800rpm
Oil temp: 202F
Oil pressure: 54psi
Water temp: 190F #9 HI-TECH HTO 10W-60 SYNTHETIC
RPM 3000 3500 4000 4500 5000
Ft-lb 259 294 306 294 275
HP 148 196 233 252 262
Maximum HP: 263.1 @ 4950rpm
Maximum Torque: 311.6 @ 3900rpm
Oil temp: 211F
Oil pressure: 55psi
Water temp: 188F #10 AMSOIL 2000 20W-50 SYNTHETIC
RPM 3000 3500 4000 4500 5000
Ft-lb 262 297 305 296 274
HP 149 197 232 253 260
Maximum HP: 261.7 @ 4950rpm
Maximum Torque: 312.3 @ 3700rpm
Oil temp: 200F
Oil pressure: 52psi
Water temp: 190F #11 MOBIL 1 0W-40 SYNTHETIC
RPM 3000 3500 4000 4500 5000
Ft-lb 268 311 304 300 283
HP 152 207 231 257 269
Maximum HP: 270.5 @ 4950rpm
Maximum Torque: 318.3 @ 3700rpm
Oil temp: 206F
Oil pressure: 52psi
Water temp: 190F #12 CASTROL R 10W-60 SYNTHETIC
RPM 3000 3500 4000 4500 5000
Ft-lb 265 285 308 284 273
HP 151 190 235 151 260
Maximum HP: 265.2 @ 4800rpm
Maximum Torque: 316.5 @ 3700rpm
Oil temp: 195F
Oil pressure: 55psi
Water temp: 190F

Horsepower Comparison Chart

RPM Shell Plus Castrol SLX
0-30 Mobil
5-50 BP Visco
5-40 Torco 20-50 Royal Purple Shell Ultra 15-50 Hi-Tec
10-60 Amsoil
20-50 Mobile
0-40 Castrol R
10-60 3000 145.8 149.4 155.6 150.3 150.1 151.5 157.4 148.4 149.4 152.8 151.4 3500 180.9 193.8 197.0 190.7 200.4 205.3 202.3 196.3 197.9 207.5 190.5 4000 228.5 229.6 232.7 232.9 232.0 231.9 229.7 233.5 232.5 231.6 235.2 4500 249.4 251.3 252.9 255.5 252.1 257.2 256.3 252.1 253.5 257.5 251.9 5000 255.7 259.6 261.3 258.2 260.0 266.6 260.7 262.0 260.8 269.8 260.7 Max 256.2 263.7 261.3 260.7 260.3 231.9 260.7 263.1 261.7 270.5 265.2 @ 4900 4900 5000 4900 5000 5000 5000 4950 4950 4950 4800
HORSEPOWER
During our dyno testing, COME did its best to ensure all parameters such as barometric pressure, room temperature, fule pressure and water tests. While we did monitor oil temperature and pressure, we have only displayed horsepower and torque, plus footnotes on temperature and pressure. For each oil we averaged three runs noting power figures at 500rpm increments from 3000-5000rpm, and peak power and torque.

Notes: Before drawing any conclusions, three "most powerful" oils, namely the Royal Purple, Castrol SLX, and Mobil 0W-40 are all zero-based viscosities, meaning naturally less friction. Next in line are the 5W+ oils of Hi-Tech, Castrol R, Mobil 1 5W-50 and BP Visco 5000 followed by the only grade of oils actually recommended by the manufacturer, Shell Torco, and AMSOIL. Note also around 4000rpm the power produced is very similar across the range and it's only really the top end where there are substantial differences. That said, the AMSOIL, Castrol R, and Mobil 5W-50 prove themselves very well.
PRICE GUIDE (FIVE LITRES)
Shell Helix Plus $23.75
BP Visco 5000 $43.90(4L)
Mobil 1 5W-50 $44.95
Castrol R $49.75
Shell Helix Ultra $50.95
Hi-Tec HTO $55
Royal Purple 21 $65.00 (4L also 18 litre)
Torco MPZ $75
AMSOIL 2000 $87.50
Mobil 1 0W-40 $94.00 (4L)
Castrol SLX $50
Torco MPZ additive $34 (500ml)
CONCLUSION
There are many names, numbers, values and suggestions throughout this article, and to an extent many of the results show how even the oils are. The one point proven is just how much better synthetic oil is over a "mineral" or petroleum based product.

In the case of a pure performance or race engine where power is priority and oil changes can be frequent, the 0-30/40 oils such as the Mobil 0-40, Castrol R, or Royal Purple would be best suited. However, for regular street-driven engines, it would be better to look at an oil with a good service interval.

An overall analysis of the 11 oils suggests in any case, see your owners manual for the recommended grade of oil. Torco and AMOSIL supplied the "recommended" oil for our testing, but added if it were an outright horsepower shootout, they too would have supplied a zero weight oil.

Although we've provided criteria to pick and choose an oil, the stand-out to us appears to be the AMSOIL, rating well in the viscosity and producing good horsepower.

In the 0 up to 40 weight category, it seems Mobil's new 0W-40 produces terrific power, insignificant viscosity loss and a middle-to-fair wear particles rating.

With the variety of grades, use this test as a guide but always follow the manufacturer's recommendation. But if we were to stick our neck out in anticipation of the law suits, from the information we gathered specific to the supplied oils in this test, we'd rate the oils in the following order:

1. AMSOIL
2. BP Visco 5000
3&4. Both Mobil 1 (difference between price)
5. Hi-Tec HTO
6. Shell Helix Ultra
7. Royal Purple
8. Castrol R
9. Castrol SLX
10. Torco

 

Which viscosities does the British manual recommend?
I suspect that the NA 5W-30 is more about getting as good as possible EPA mileage rating, i.e., the lowest possible viscosity to reduce friction.
I saw 5W-40 on the UK Castrol site as suitable for the XJ8.

 

I am running 10w-30 instead of the 5w-30 because i am in a hot climate that never gets below freezing. Is this a good idea or should i go back to 5w?

 

If you want to dig around the interweeb long enough, you'll find dozens of similar shoot-outs testing the same or similar oils. No two of them come to the same conclusions.

 

What I found most interesting was the difference in HP and torque.

If you extrapolate to 400HP engines the gain of about 15hp with some of these oils would be nearly the same as changing to a free flow exhaust system.

And yes science is bias dependent...endless regression.

cheers,

jj

 

'Power gains' due to reduced friction cannot be extrapolated with rising HP. The amount of drag on an engine at a given RPM and temperature is constant.

In my early working days, I ran a production test cell doing final pass off test on 600-1500HP gas turbine engines. The variations we would see on a given engine just from shutting it down, going for lunch and firing it up again would greatly exceed the scatter seen in the quoted tests, never mind changing something like draining the oil and refilling it.

These tests also never happen to mention the varation in results just by doing multiple 'pulls' on the same engine.

Speaking of pulls, go to the website article you quoted and read the very bottom where they added a small bottle of miracle juice and got 15% increase in HP. Pull the other one please

 

TSB 100-10 allows the use of synthetic 10W-40, 15w-40 and 15w-50 oils. Basically 5, 10 or 15W with either 40 or 50 weight. 10W-30 is not mentioned.
Is it doing any harm? With such a broad range of tolerated oils, I doubt it.