10w40 vs 0w40

[mclasser]

My Infiniti burns ~1 qt of 5w30 every 6k miles. Different oils -- HM, syn or dino -- don't make a difference. I know that's not much usage but I'd like to do a summertime run with 10w40 to see if it helps any. The owner's manual says 10w40 is okay to use above 0° F. I used M1 0w40 once and liked how smooth the engine sounded. It didn't help much with the consumption, but then again it can take a few OCIs to see a difference. I remember reading on here that some oil burning can take place during cold starts. With this in mind, some questions: - Will the lighter 0 wt oil burn more easily than a heavier 10 wt on cold starts? - At operating temp, should a 0w40 & 10w40 have the same thickness? - This car often gets short tripped <5 miles. Is it risky to run a 40 wt oil, since even in the summer, this isn't sufficient time to fully warm it up? Thanks for the info in-advance, guys.

 

[Gokhan]

xW-40 is OK. 10W-40 is cheaper. Don't worry about cold starts. You can also use 15W-40.

 

[Kira]

Hello, I trust smarter people will chime in to answer your questions and debunk my misinformation. I've read here that cold starts contribute to consumption with the 10W-40, when "permitted", being a great first remedy. It's good the M1 0W-40 did help some. How much, by the way? With that in mind I'd submit that the Castrol 0W-30 European Formula (which was always credited with being thicker at temperature than the Mobil1 0W-40) might be a good product to try. PERSONAL NOTE: I just used my last Castrol 0W-30 and have only seen the emplacement 0W-40 EDGE product. In answer to your 3 questions: 1) I do believe the lighter 0 weights burn cold more readily than the corresponding 10 weights. Bring on the knowledgeable people, please. 2) Yes, I believe they thicken the same way but there are a myriad of differences among products. Bring on the knowledgeable people, please. 3) No, you have nothing to worry about regarding not fully warming up as far as unfolding the polymers in oil goes. You have more to fret from moisture not being boiled out of your motor oil with short trips. Bring on the knowledgeable people, please. I just changed the oil in my '99 Saab turbo to the Castrol 0W-30 and I too conclude it is superior due to its quietness. I'd go for the 10W-40 because it's Spring and I assume your Infinity has 140K on it. Kira

 

[Charlie2015]

Mobil 1 HM 10w40 or Maxlife synthetic blend 10w40 are two oils to consider.

 

[Kuato]

Originally Posted By: mclasser

- Will the lighter 0 wt oil burn more easily than a heavier 10 wt on cold starts?

Yes, probably. This is IMO.

Originally Posted By: mclasser

- At operating temp, should a 0w40 & 10w40 have the same thickness?

Yes, assuming same HTHS and specifications.

Originally Posted By: mclasser

- This car often gets short tripped <5 miles. Is it risky to run a 40 wt oil, since even in the summer, this isn't sufficient time to fully warm it up?

Not risky.

 

[SR5]

Most spec sheets I have looked at show the 10W40 to be thicker at both 100C and 40C than a typical 0W40. To me this makes a 10W40 better at reducing oil consumption, as long as you are above 0F (-18C) in temp. A mineral 15W40, especially a HDEO like Delo or Rotella, will be thicker again, as well as requiring a slightly warmer environment. I would try a 10W40 like Valvoline MaxLife semi-synthetic (red bottle).

 

[901Memphis]

It's fine to use 10w40 in a 5w30 application down to 0F. id also recommend Maxlife 10w40

 

[FCD]

1qt. Every 6000 is not bad at all, i would try out Valvoline Maxlife 5W-40.

 

[RationalRussian]

What about a 20-50w if the 10-40w doesn't slow consumption? Is that too extreme?

 

[Quattro Pete]

Originally Posted By: mclasser

My Infiniti burns ~1 qt of 5w30 every 6k miles. Different oils -- HM, syn or dino -- don't make a difference. I know that's not much usage but I'd like to do a summertime run with 10w40 to see if it helps any.

FWIW, I went from a Euro 5w40 oil to HM 10w40 oil in my 530i. It made no difference in terms of usage - still consuming about 1qt every 3k miles.

 

[SR5]

Originally Posted By: Quattro Pete

FWIW, I went from a Euro 5w40 oil to HM 10w40 oil in my 530i. It made no difference in terms of usage - still consuming about 1qt every 3k miles.

My old Audi consumed a lot of 10W40, so I stepped it up to Shell Helix HX7 15W-50 HM, but it made no difference and drank just as much. So I stepped it up again to Penrite 20W-60 (the HPR 30) and suddenly no consumption issues and yes the car started easy as pie even on a winters morning. But I do live in a warm climate.

 

[asiancivicmaniac]

Is it actually burning? Or do you have a leak somewhere too? My Max with the same engine. has an oil leak and thicker oil doesn't do much. It burns a little too, but most of the loss is from leaking. If you want to run a 40 weight, how about Shell Rotella?

 

[steve20]

OP--have you checked the PCV system (valve & all relevant hoses) are clear, & working properly? Just a thought Steve

 

[mclasser]

Kira- M1 0w40 didn't help with the consumption. Asiancivicmaniac- No visible leaks. I've considered 5w40 but the possibility of cat damage with gas engines concerns me. Steve20- I plan to change the PCV valve when I do a full tuneup this summer. These VQ35s are known burners but the PCV system isn't problematic.

 

[EP777]

Here are the differences in cold, hot, and HTHS.

 

[901Memphis]

Originally Posted By: RationalRussian

What about a 20-50w if the 10-40w doesn't slow consumption? Is that too extreme?

Yes 20w50 is too extreme