basic oil grade questions

[mikeinaustin]

I have an infiniti g35 coupe with the vq35 engine.

the manual specifies 5w30 is preferred but 10w30 and 10w40 can be used if the temp is greater than 0f. where i live (central texas), this means 10w40 is fine year round.

here is my question, since 5w30 is fine and 10w40 is fine imply that 5w40 is fine as well?

do you consider the vq35 to be a high rev engine (seems to basically always run around 2700 rpm during normal highway driving)?

what grade oil would you run in this engine for temps that pretty much average 80s to low 100s year round?

 

[bruce381]

5/30 or 10/30 would be fine
bruce

 

[mdocod]

my 3 speed automatic susuki swift probably runs well over 4k at highways speeds, though it is not a big engine, (in the market of engines out there, this stacks up as about a weedeater engine)

My isuzu rodeo runs over 3k in 5th gear at 75mph.

The accord that I owned awhile back, was over 3k at 75mph.

The only cars you will see than run "low" rpms at highway driving are those with big engines and big torque. (cadilacs with V8s have very high gearing, run under 2k on the highway)


more importantly to mention, is that, generally speaking, engine wear is not as heavily related to RPMs as it is to the load that it is under. engines that run for extended periods under full "load" in a high gear will wear more metal than engines running in a lower gear reving a bit higher with less load/revolution.

In your climate, you could use just about any oil you want to. I would suggest 10W40 since it is listed by the manufacture. You could probably even run straight 30 weight oil.

I doubt you would have any problems with 20W50 weight in that climat.

 

[TallPaul]

My experience is that an engine will run a bit hotter with higher RPMs. My pickup (4.9L) runs 2000 rpm at 70 mph. In 4th gear it runs 2500 at 70. If I run 70 mph in 4th the oil pressure will drop a few psi, which tells me more heat is being generated. That is with 10w40.

Anyway, in Texas you would want to run a 10w30 or 10w40 or some combination (mix) of the two. My wife's Aerostar tends to run 2600 rpm at 70 mph (3.0L). I run a thickened 10w30 equal to roughly 1/3 10w40 and the rest 10w30.

 

[Max_Tl]

mike,

I have a 3.5 VQ too, recently returned from a weelong trip thru our 'peach valley' where daytime temps were 28-35C (80-90F?) on Castrol gtx 10/30. speeds were 110-140kmph (70-85mph) rpm about 2600-3000. engine reved freely even in the high mountain passes (+9000') no uoa's done.

but back to your post, have run Esso XD3 0w30, which doesn't sound like it's avail there yet... it seems to have a very close cousin the GC 0/30 ('04 dated, also can run year round - that has recieved favarable reviews here & on the maxima boards.

 

[ssls6]

quote:

---

here is my question, since 5w30 is fine and 10w40 is fine imply that 5w40 is fine as well?[/QB]

---

Yes. In fact, I bet your motor responds well to some of the 5w-40s on the market.

 

[Big Jim]

As long as many opinions have chipped in here, I'll toss my $.02 as well.

Yes, you can run most any oil you want in Texas.

I would run 5W30. My Motorcraft rep and Ford Motor Company did a pretty good job of convincing me that "thinner is better" as long as the engine was designed for it. I run 5W30 in one car and 5W20 in the other car. My climate in California isn't all that much different from Texas.

 

[mikeinaustin]

quote:

---

Originally posted by ssls6:

quote:

---

here is my question, since 5w30 is fine and 10w40 is fine imply that 5w40 is fine as well?

---

Yes. In fact, I bet your motor responds well to some of the 5w-40s on the market. [/QB]

---

i am leaning toward mobil 1 truck and suv 5w40 and amsoil 5w40 european formula right now.

 

[medic]

Okay, you are obviously looking towards synth oils. If you are going to run a synth oil, you can take what the manual says and throw it out the window. The manual assumes that you ae going to run dino and makes recommendations bases on that assumption.

You can run anything from 0w,5w,10w - 30,40. Mix and match as needed.

 

[jorton]

Yes that's high revving for a passenger car. So I would say use 5w-30 synthetic or 5w-30 high mile dino.

Most 5w-30 is thicker than it's 10w-30 big brother and 40 is too thick.

If the 5w-30 high mile shears a little it'll still be a 30 because it's around 35 to start with.

Later on, get an UOA and if the lead is high, then switch to 40.

 

[TallPaul]

quote:

---

Originally posted by mikeinaustin:
i am leaning toward mobil 1 truck and suv 5w40 and amsoil 5w40 european formula right now.

---

Take a look at Valvoline Synpower 5w40. Some excellent specifications including BMW, VW, etc. Valvoline product data sheets.

 

[427Z06]

TallPaul, did you name one of your kids "Valvoline"?

A quality synthetic 10w30 should provide all the protection the vq35 engine needs, even in Texas. I'd run a quality synthetic 5w30 in the winter unless you garage it.

 

[Doug Hillary]

Hi,
TallPaul - yes, I think Valvoline Synpower 5w-40 with the Euro "qualifications" from well known Manufacturers and the ACEA sounds like a great product
It is readily available in OZ too but I have never used it

As a matter of interest it is Porsche Approved and Listed - in both 0w-40 and 5w-40 viscosities

Regards
Doug

 

[TallPaul]

quote:

---

Originally posted by 427Z06:
TallPaul, did you name one of your kids "Valvoline"?

---

I guess I could have his name change, but wife would never allow it.

Maybe I should change my name.

 

[mdocod]

something about the name "Valvoline" implies to me they were trying to imply that their oil is superior in protecting the valve trane.

WHAT ABOUT THE REST OF THE ENGINE?

should have called it valvomainbearingrings'n'thingsoline

hehe. just kidding of cource.