Is anyone know the different between Full synthetic and Syntec Blend?

 

Yes, but probably not to your engine if you are following the recommended change interval.

I've also heard Wal-Mart Super Tech is a great buy for a synthetic...

My personal experience with Syntec ensures I will never buy it again, but many others do not feel the way I do, and have reasonable results to back it up. Brand really is pretty inconsequential once you've jumped the hurdle to synthetic even if it's just a blend.

 

Interesting, do you know who mfrs the oil for Wal-Mart ??? I know that Champion Labs makes their oil filters (SuperTech label), so I wouldn't hesitate to use their oil filters. I've noticed that the SuperTech items are as much as 50% less than the national brands, but in many cases are mfr'd by the same national brands . . .

 

If this is true then how come we can expect better performance with higher level octanes than recommended? If 91 octane doesn’t cause pinging, then putting 94 octane shouldn’t change the ECM calculations by this reasoning, no?

p.s.Anyone that is interested, there is an episode of Fifth Gear from last year testing different octanes vs performances.

 

You can't expect better performance if the base fuel meets the minimum required octane for the engine. More is not better, but not enough is far worse.

I've actually seen some Supras lose power on dyno tests from excessive octane (you really don't need C-16 at only 22 psi), so I would be extremely skeptical of anyone claiming better performance from higher octane - unless the ECM is detecting knock and retarding ignition timing to compensate.

The other difficult to quantify variable these days is oxygenate type and content. Alcohol has a much lower specific heat, but a much higher oxygen content, so it shows up frequently as a "clean" fuel. Your mileage will certainly be worse because the specific heat is lower in any fuel with alcohol in it. Also oxygenates like MBTE may help finish the combustion process, but they will cause your ECM to compensate for their oxygen content at any point in closed loop operation. The bad part about this is when you change fuels.

Your short term fuel trim will be adjusted to compensate for the new fuel with less oxygen (because the ECM is constantly trying to maintain stoichiometric ratios), and it doesn't happen instantly. If the disparity is great enough it will also affect long term fuel trim. So, in order to do any kind of testing, you need to reset the ST and LT fuel trim values to the factory presets and allow the ECM time to adjust for the "new" fuel if you expect optimum operation. You also need to be sure you've reasonably purged the fuel system so there isn't a mixture of fuel A and fuel B. It's not quite as simple as it would seem.

 

Lobux, you're confusing the ***** outta me. In CA, how do I know the difference b/w oxygenated or alchohol based gas ? Make it simple for me, which brands can I trust and which should I avoid . . .

 

On the turbocharged Audi S4 I had, third party vendors sold ECM chip programs optimized for race gas. If you had one of those, you'd fuel up with 100 octane, press a button on a fob or dongle to switch from the 91 octane program to the race gas program, and the ECU would switch to different timing, boost and fuel maps that would take advantage of the higher octane. Made a big improvement both on the dyno and at the drag strip.

 

Useful post, as written by iwilson on Elisetalk.com:

"Not all synthetic oil is really synthetic. The old adage you get what you pay for really applies when it comes to oil.

Synthetics can be broadly broken down into three types:

* Group III Hydrocracked:- Derived from normal mineral oil, technically not synthetic, but owing to lawyers getting involved can be sold as such. Lots of it on the market. Not bad stuff, but it's still Dino oil at the end of the day.
* Group IV Polyaphaolefins or POA's:- The real deal, made in the lab by guys in white coats. Mobil 1 is an example or *used* to be - they now mix in some hydrocracked basestock.
* Group V Polyol Esters:- The Rolls Royce of the synthetic world. Provides even better lubrication than POA's. Expensive but worth it if you're caning the engine. Motul, Redline, Amsoil, Silkolene and Royal Purple are examples. I personally use Motul 300V double ester.

The lawyer bit relates to a court case involving Castrol. They changed their formula from a group IV base stock to using group III. Mobil took them to court and unfortunately Castrol won. As a result a lot of companies changed their formula as well. So most of the so-called synthetics on the market today are based on inferior group III base stock. One major short coming of group III oils are their change in viscosity over time. This means for e.g. that a 40 weight oil will turn into a 20 weight oil. This is because group III oil doesn't have good shear resistance - meaning that the molecules get chopped up reducing the rated viscosity of the oil. Group V oils have excellent shear properties and maintain there viscosity for life of the oil. In addition group V oil provides excellent startup protection, lubricity and fuel efficiency. This is due to their attraction to metal surfaces. They are also excellent at preventing sludge and varnishing. Group IV oils are poor in this area and are often mixed with 10/20% group V base stock. Group IV and V oils are thermally more stable with good low and high temperature performance.

I certainly wouldn’t use anything less than a group IV oil, especially if your engine is mainly used on the track."



For what it's worth, I use nothing but Motul 8100 in my cars, very noticeable difference in performance.

 

Group V: only needed for true racing
Redline
Motul

Group IV: Best for long drain intervals, towing, high temps, hard driving ie track days
Mobil1 Tri-synthetic (discontinued)
Amsoil
Mobil 1 Super-syn is closer to a group III lube but have multiple patents on a new molelecule that should keep it as a top tier product

Group III: cheap synoils. Buy only if the price is right as they are inferior to Group IV products which typically cost little more
Castrol Syntec
Valvoline Synpower
Pennzoil Synthetic
Havoline Synthetic, Exxon synthetic etc (some of the best priced synthetics around)

Group II: Highly refined mineral oils
Valvoline All climate
Pennzoil PZL turbo (Very good product except below 15 degrees)
Royal purple.

 

There's a missing piece to this puzzle. The base oil they refer to is the base oil used for the additive packages. The actual base stock for the oil has to be some kind of synthetic in order to be called synthetic according to the documents I read on the Castrol case. Mobil used to have this information on their website. So the non-synthetic oil is typically about 20% of the oil's compostion because it contains the VI modifiers and other additives typical of modern oils. The remaining 80 percent is still required to be synthetic.

I followed this with great interest when it happened because I had an engine in a brand new car using Syntec that consistently burned a quart of oil every 2000 miles. I have never put it in anything I've owned since.

 

So where does Royal purple fall? Group V or group II?

Javier

 

I had a Corvette and a MB that both had factory fill of Mobil 1. I stay with the factory fill. I will probably do the same on the IS 350.

Aloha,
Larry

 

Been using the german made LUBRO MOLLY VOLL-Synthese for years(comes in 5 liter purple container). I wonder what group it belongs to.

 

I might as well ad to the questions; is the new Mobil 1 Extended Performance a grade IV or better?

 

Ha! Good spot, guess I wasn't reading it carefully enough. If I had to guess, I'd bet that there's different varieties of Royal Purple floating around out there? Do a Google search, there's articles everywhere about these synthetic categories.