Synthetic 5W40, Cool!

[Dbeck002]

The other day I noticed some Mobil 1 5W40 synthetic. I never saw this Mobil1 viscosity, is it new? I might use it, would be great for cold starts and hot days.

 

[Black 93 Fox]

I wouldnt put synthetic in a high mile motor if you have one.

 

[sgarlic]

I swapped my wifes Jeep ZJ to Mobil 1 at 166k. It's fine. I swapped my '88 to Mobil 1 at 130k. It's fine.

People who say not to haven't read up. You may develop a leak or two, but if you do, just replace whatever's leaking.

Bottom line: synthetic is so much better for your engine, it's worth replacing a few gaskets.

 

[ninety15.0]

whats the deal with syn. blends...are they worth it or should i just go with a full syn.? its a brand new motor that will be broken in with conventional then switched over? thanks

 

[Dbeck002]

I was talking about the viscosity. 5W40 would be great for the florida heat. 5 weight on startup and then 40 while hot. Better than 10W40 IMO. I might start using this.

 

[HISSIN50]

Yep, I think the oil mentioned is from their Truck and SUV line. HDEO's have been using that viscosity for a bit now.

 

[stangbear427]

I swapped my wifes Jeep ZJ to Mobil 1 at 166k. It's fine. I swapped my '88 to Mobil 1 at 130k. It's fine.

People who say not to haven't read up. You may develop a leak or two, but if you do, just replace whatever's leaking.

Bottom line: synthetic is so much better for your engine, it's worth replacing a few gaskets.

External leaking is only the logical problem from using synthetic. The main problem is that it burns clean- if there is a problem INSIDE the engine it won't smoke, so you won't know about it. Dealerships have seen brand new engines trashed internally because something was wrong and the customer ran sythetic, so nobody even knew there was a problem until it was too late- ran like a champ until after the damage was done. It doesn't matter how old the engine is or how many miles are on it, leaking isn't the issue. Older engines are more prone to this kind of problem- that's why it isn't recommended for high mile engines- nothing to do with bad gaskets. Yes, it provides superior protection. What they don't tell you is that you can get the same protection from running one quart of sythetic with four quarts of normal oil as you would with five quarts of strait synthetic. Working in the garage I've seen far more problems caused by synthetic than prevented- read all you want about it. I believe what experience has shown me, not what the propaganda says.

 

[vristang]

External leaking is only the logical problem from using synthetic. The main problem is that it burns clean- if there is a problem INSIDE the engine it won't smoke, so you won't know about it. Dealerships have seen brand new engines trashed internally because something was wrong and the customer ran sythetic, so nobody even knew there was a problem until it was too late- ran like a champ until after the damage was done. .

A brand new engine get trashed internally because somthing was wrong with it. But it is the customers fault, because they ran synthetic oil!!!

With all respect this sounds like something I would hear at a Ford dealership. Ford has a way of saying anything to shift the blame onto the customer, and this is a prime example. If there was a problem with the motor, the mechanic should have caught it, Period. That is what they make their living doing, they should be damn good at it. If not they should at least be better than my hack-@$$.
The last time I took my car to a dealership was for a brake inspection. Not repair, just inspect. Before handing over the keys I turned the sound system off. When I picked the car up the sound system was dead. When I brought the car back to have the dealership fix it, they looked at it for an hour, then told me that the car stereo shop had messed up on the install and that they didn't do anything that would have caused the problem anyway. I have had that system in place since 97 and have never had any such problem. How do you blow a fuse to a stereo that is turned off, while doing a brake inspection? HACK is how.

Sorry for the rant, but I can't stand to hear anyone talk up dealership mechanics anymore.

Synthetic oil was not the cause of any of the failures you described. Don't jump on the Dealership Tech bandwagon and only believe what the old time techs tell you is the truth.

 

[Michael Yount]

I've used 5W-40 Shell Rotella T diesel rated synthetic oil in my wife's BMW for quite some time (it has 80k on the odo). I can run that weight year-round here in east TN. Her car came with synthetic new - and the oil change interval software bases it's change intervals on the use of synthetic -- which can tolerate much longer change intervals without significant lubricity breakdown.

Stangbear (howdy!! where you been?) - not sure where your info is coming from, 1 qt. synth added to regular oil doesn't offer the same benefits/protection of running all synthetic. And the Mobil1 synthetic I used to run in my SCCA racer smoked blue just like dino oil.

Synthetic is a definite plus if you're operating a vehicle with extremely cold starts or for extended time periods at extremely high oil temps. Its cold pour points are MUCH lower than regular oil, and it will take much longer high temp abuse than regular oil. I used nothing but synthetic lubricants (tranny, rearend, engine, wheel bearings) in my racer as it really put a beating on the lubricants racing back in Texas in July and August - not uncommon to see 20 minutes to 2 hours with coolant temps at 220F and oil temps in the 250F-290F range.

However, most of us don't face those conditions on a regular basis. For street cars, even occasionally raced, clean frequently changed dino oil of the appropriate viscosity will lubricate an engine just as well as synthetic oil will. You might free up a couple of HP with a lighter weight synth -- but if you change dino oil and filter regularly, most any car should go for way more miles than any of us are likely to put on one.

As for leaks - what happened on one person's car is simply not indicative of what's gonna happen on someone elses. Never ceases to amaze me the extrapolations that go on "....it worked fine in mine, therefore it will in yours too..." Some high mileage switches to synth work without a hitch. And some result in significant oil leakage. Even though non-predictable, the issue is pretty well documented - over time (years and high miles), tiny porous areas in seals/gaskets get sealed up with sludges/gums/varnishes from dino oil. The better detergent properties of synth. oil can clean out those deposits that are acting to seal a tiny hole in the seal/gasket. Freed of the hole-sealing sludge, the slippery synth seeps out the formerly sealed weak spot. Blame it on the oil - blame it on the gasket --- it's what in some circles is often referred to as a distinction without a difference. The simple fact is that if the switch to the higher-detergent action synth hadn't occurred, oil wouldn't be leaking out of the engine.

I've switched 4 street vehicles over the years each with at least 80K on them. All 4 leaked after the switch. The switch simply wasn't worth the gain (negligible on a street car) -- no more swaps after the 4th leaker. Yes - I'm a slow learner.

Will yours leak? Try it and tell us. That's the only way we and you will know.

 

[stangbear427]

A brand new engine get trashed internally because somthing was wrong with it. But it is the customers fault, because they ran synthetic oil!!!

With all respect this sounds like something I would hear at a Ford dealership. Ford has a way of saying anything to shift the blame onto the customer, and this is a prime example. If there was a problem with the motor, the mechanic should have caught it, Period. That is what they make their living doing, they should be damn good at it. If not they should at least be better than my hack-@$$.
The last time I took my car to a dealership was for a brake inspection. Not repair, just inspect. Before handing over the keys I turned the sound system off. When I picked the car up the sound system was dead. When I brought the car back to have the dealership fix it, they looked at it for an hour, then told me that the car stereo shop had messed up on the install and that they didn't do anything that would have caused the problem anyway. I have had that system in place since 97 and have never had any such problem. How do you blow a fuse to a stereo that is turned off, while doing a brake inspection? HACK is how.

Sorry for the rant, but I can't stand to hear anyone talk up dealership mechanics anymore.

Synthetic oil was not the cause of any of the failures you described. Don't jump on the Dealership Tech bandwagon and only believe what the old time techs tell you is the truth.

No problem, we all have our rants to get out. I'm not supporting dealers- most of the time I recommend private shops. In most regards, I can't stand to talk technology with old time techs anymore. I've been in this business almost two decades, and come from a family of mechanics. The opinion I gave comes from an ASE certified master tech who was not trained by a dealer. I'm not saying synthetic damaged the motor in any way, I'm saying it disguised the problem that was already there. It's rare, but engines do come off the assembly line defective and it's impossible to know until they start to show symptoms. If these symptoms are hidden, things can get way out of hand in a hurry. Almost every engine builder I know recommends using conventional oil until well after the break in period for this very reason amongst others. I know several- and they build race car engines for the speedbowl, not commuter crap or even quarter mile warriors- we're talking 100 lap endurance racing. These guys know their S#!+. I know the owners and techs in almost every shop in this area, and I can say with impunity that there are just as many hacks on both sides of the fence. I don't patronise the dealers regardless... but I don't have to. I hear stories like yours all the time- and I agree. For what they get paid, we expect more from them than blame shifting. I don't want to think about what they would have had to do to blow a stereo fuse on a brake inspection, but it doesn't surprise me. I've gotten taller tales from Mercedes dealers if you can believe it. This all doesn't change the fact of the matter though- be very carefull with synthetic oil. It doesn't matter who's fault it is or who should have caught it before it got out of hand, it's like putting on a blindfold before raiding a terrorist camp because you should be trained enough to smell them. That's all fine and good, but it isn't always that simple. Every engine is a unique case, and you don't always know what's going on inside unless it tells you somehow. No matter how good you are, if it only whispers...

Hey Michael! I've been in and out, post here and there. Real, real busy- not much typing time these days... looks like we've grown about 10K members since I was a regular. I didn't think I'd be missed with all the expertise in here, so I took some time off. More on topic- I've seen some synthetics with an additive that show some combustion problems like conventional oil, but I've also seen some independent testing that showed other problems. Don't remember what they were, so I'll just leave it there. I wouldn't try to go sythetic change intervals with only one quart in there, but otherwise it's pretty much an even shake. Like you, after ten years of watching this stuff evolve and working with it I've pretty much decided it wasn't worth it. Just turned over 253K on the 'ol GT today... I ain' even trying it in this mill. Ha! Datsun pickup engines were going a million miles on conventional oils decades ago, so apparently it isn't that big a deal. Not to mention it DOES get cold up here in CT, I envy your climate. Now, that all being said, I strongly recommend synthetics in the other areas mentioned- tranny, rear end. In the engine though, I'll settle for a hybrid.

*edit- way off topic... vristang, is your avitar a Civic with a Terminator engine? It's gotta have a story behind it, I have to ask

 

[vristang]

My avitar came from an importer site. Some guy was trying to sell his Civic, which he claimed to run in the nines (I think), and be streetable. Sticking out of the hood is the Turbo. The thread that he started to sell the car was a good 20 pages if I remember right. That's 20 pages of him getting reamed by people from every imaginable site, including here. If you can find the link on this site, it is good for more than a couple of laughs. It turns out that ricers hate stupid people just like any body else.

I use the avitar to remind myself that no matter what your intentions it is easy to get carried away and do something stupid and tasteless with a car.

Sorry again for the rant, but damn it was fun!

I love using synthetics in the rear, trans, and p/s pump. All of them make alot less noise with the synth, but I would not be able to tell if I get more power. I am waiting to put synth in the motor until it breaks in (up to 170miles now!). I will make the switch because with the amount of time and money I have tied up in the motor, I would feel stupid for not making the change. Just my opinion after getting a Degree in Auto Design.

 

[stangbear427]

A streetable 9 second Civic... yeah. I could see that getting funny. His G-tech tell him that? Maybe in the 8th mile. It's hard to see in the little pic, but it looked like that fancy belt cover on the '03-'04 Cobra sticking out. Thought it had to be a photochop.