Cold climate 0w40 or 5w40?

I have been using Motul x-cess 5w40 but am thinking about switching over to x-max 0w40 for the winter. They are pretty similar, I think its just marketing between the oils but you can only get 0w40 as x-max. I am thinking the 0w will provide better cold start flow and protection.

Any oil nerds know if there will be any difference between 0w and 5w during cold start?

X-cess
https://www.motul.com/system/produc...ts/2698/8100_X-cess_5W-40_(GB).pdf?1302646818

X-max
https://www.motul.com/system/produc...original/8100_X-max_0W-40_(GB).pdf?1449520180

I'm not sure it makes a difference unless you live in Alaska. Heat is a greater concern for my GTI. I like the thicker oils, 5w40.

For what it's worth, I've been running 0w40 in the winter and 5w30 in the summer with great results. I wouldn't consider myself an oil guru, but I have tested literally 15 different oils on the GTI's over the years and found this to be the best weights to run in the respective seasons. I also send my oil out for analysis and have gotten good reports on them.

I do feel like the car runs better in the winter on the 0w40, definitely starts much smoother.

Any recommendations for a 502/505 approved 0w40. I can get Motul 300v easier and cheaper than x-max., nobody carries the 0w40

gti2slow said:

Any recommendations for a 502/505 approved 0w40. I can get Motul 300v easier and cheaper than x-max., nobody carries the 0w40

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I have read up on this a little bit on bobistheoilguy.com and the oil-nerds over there generally agree that 0w oils are only needed in climates where its colder than about -20F when you are starting your car in the morning. I've been using Rotella T6 5w40 year round without any issues in NJ. This oil greatly reduced my cam follower wear compared to "German" Castrol 0w30 that I ran for the first 50k.

Shell now offers a Rotella T6 0w40 if you feel like its cold enough in your area to warrant it.

I ran Mobil 1 0w-40 in my MKV for most of the time that I owned it. Burned off less than Castrol 5w-40 and Rotella T6. Also on the Rotella, keep in mind it's not VW approved in case you still have cam follower warranty or something.

I'm currently running Castrol 5w-40 in the MK7. Thought about 0w for the winter, but since it never really gets below 20* F here in Georgia, it probably wouldn't pay off.

I really don't get the cult following of Rotella T6, is it 502/505 approved?

Motul's site should have the pour data for each oil on the MSDS sheet - that will tell you how they behave when stone cold

T6 following is for 2 reasons - easily accessible, and inexpensive. It's a good oil overall, as are many, many, many oils out there

gti2slow said:

I really don't get the cult following of Rotella T6, is it 502/505 approved?

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It is not on any VW approved lists. From what I understand, this is due to the fact that the additive pack is loaded with antiwear metals (ZDDP), in concentrations that can possibly effect the lifespan of the cat converters (not a problem on stage 2 and over). Shell put so much antiwear additive in because it was formulated specifically for diesel engines, which tend to torture motor oil.

My theory for the root cause of the VW hpfp cam follower fiasco is that VW (Hitachi) introduced a flat-tappet based fuel pump at the same time that nearly all auto manufacturers transitioned to completely roller-based valvetrains, which was done in conjunction with motor oil producers lowering ZDDP concentrations due to environmental concerns.

Using a high ZDDP oil like Rotella, which is designed for flat-tappet valvetrains, showed significantly less wear on my hpfp cam follower. The added ZDDP will also only help reduce wear everywhere else in the engine. The only concern would be running this oil through the stock cats for the life of the vehicle.

A added bonus is that it is dirt cheap at Walmart.

It's why I use the 8100 x-cess, they have a decent amount of zinc and phosphorus additives without going into extreme amounts.

I buy in bulk and an oil change with filter is about $40, cost is marginal compared to a engine rebuild to clean bits of hpfp shrapnel out.

Just keep in mind that "high" levels of ZDDP is always subjective. The MSDS sheets tell all. Oils that don't advertise particularly high ZDDP often have it in higher concentrations that oils that do advertise as such. But a lot more goes into the "right" oil, or "good" oil than the amount of zinc, etc.