Best oil weight/viscosity for a bone stock car's first track day?

[shijima_ending]

Hey all,

I know the subject of engine oil has been discussed extensively here. And before you say it, yes I did search around but everyone has different use cases, setups, and climates they are living in -- and I did not want to sift through that 14 page thread trying to find someone like me.

I have my first track day this month. It's at Buttonwillow Raceway which is essentially central California. I can expect ambient air temps upwards of 100 F and my engine is bone-stock. What weight/viscosity would you guys recommend?

As for brand, I'm pretty set on Motul's 300v but I'm open to anything else. Bonus points if it's cheap enough to warrant using it while daily driving also. Speaking of which, 13k miles in and I currently only have used Honda's Ultimate Full Synthetic 0w-20. However I do canyon runs either every weekend or every other weekend, so the car still sees action somewhat often albeit nothing like track use. Would it still be worth upgrading in general?

Thanks!!

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[StingertimeNC]

5W-30 in my opinion. Just from advice here on the forums and such. Most any full synthetic will suffice. I use Quaker State or Pennzoil Platinum. Both have the classifications required as far as I know.

 

[shijima_ending]

5W-30 in my opinion. Just from advice here on the forums and such. Most any full synthetic will suffice. I use Quaker State or Pennzoil Platinum. Both have the classifications required as far as I know.

Do you run 5w-30 just at the track or daily driving as well?

 

[AZCWTypeR]

The UK FL5 owners manual shows 5W-30 acceptable in all weather.

5W-30 provides a thicker oil film, better protecting rod and main bearings (especially important at low rpm). The crank journal literally skis on an oil film, and it sinks closet to the bearings at high load/low rpm.

0W-20 is spec'd to aide CAFE numbers. Real world fuel economy difference is near zero.

 

[shijima_ending]

The UK FL5 owners manual shows 5W-30 acceptable in all weather.

5W-30 provides a thicker oil film, better protecting rod and main bearings (especially important at low rpm). The crank journal literally skis on an oil film, and it sinks closet to the bearings at high load/low rpm.

0W-20 is spec'd to aide CAFE numbers. Real world fuel economy difference is near zero.

Correct me if I'm wrong, but overseas doesn't the K20C1 have both port and direct injection? If so, I wonder if the UK recommended spec has anything to do with that.

 

[AZCWTypeR]

Injection type not an issue as long as the 5W-30 used is the latest oil spec (SN?).

 

[J_D]

If you aren't a rockstar who's going to overheat the car stock, any quality 0W20 will be fine.

 

[shijima_ending]

If you aren't a rockstar who's going to overheat the car stock, any quality 0W20 will be fine.

I've gotten to over 230 F on the street, I wonder what I could do on a track . But that was a pretty hot day

 

[StingertimeNC]

Do you run 5w-30 just at the track or daily driving as well?

Yes, I run it always. I live in NC so pretty temperate climate although some cold days in the winter. I also change the oil just before a track event religiously, then run that oil until the next track event. At most I'm putting 2k miles on the oil and filter before a change. I usually go to the track in the spring and fall, but actually went twice this spring. I've had two oil changes this year so far and put less than 3k miles on the car. Going back in October so that will be change number 3. I'll run that oil until March.

Not that you asked about all that, LOL. But yes, run it all year.

 

[Spart]

The UK FL5 owners manual shows 5W-30 acceptable in all weather.

5W-30 provides a thicker oil film, better protecting rod and main bearings (especially important at low rpm). The crank journal literally skis on an oil film, and it sinks closet to the bearings at high load/low rpm.

0W-20 is spec'd to aide CAFE numbers. Real world fuel economy difference is near zero.

I would say that a good quality 5W-40 or 0W-40 would be a suitable upgrade for track duty.

Remember that the first number is cold weather viscosity, and the second number is high temperature viscosity. If cold weather isn't a concern, pick a 5W-something. If it is, probably stick with 0W-something.

The extra viscosity won't hurt anything but fuel economy. All of the car's functions that rely on oil pressure will do so across a wide band of viscosity, the real concern is when that viscosity gets unreasonably low and pressure drops as a result.

A 0W-30 at 210 degrees will have roughly the same viscosity as a 0W-40 at 230 degrees. It just provides you a little margin for higher temps.

 

[shijima_ending]

I would say that a good quality 5W-40 or 0W-40 would be a suitable upgrade for track duty.

Remember that the first number is cold weather viscosity, and the second number is high temperature viscosity. If cold weather isn't a concern, pick a 5W-something. If it is, probably stick with 0W-something.

The extra viscosity won't hurt anything but fuel economy. All of the car's functions that rely on oil pressure will do so across a wide band of viscosity, the real concern is when that viscosity gets unreasonably low and pressure drops as a result.

A 0W-30 at 210 degrees will have roughly the same viscosity as a 0W-40 at 230 degrees. It just provides you a little margin for higher temps.

I’ve been doing some research and it seems like there are pros and cons to both 0w and 5w — and that a perfect middle ground is 0w30

0w provides for better protection on cold starts, less friction which results in no power loss (losses of upwards of 5hp for 5w) and faster cooling. and moving up to 30 will provide better at-temp protection. and there are certain 0w oils that hold up well and don’t sheer much. let me know if any of this checks out lol

 

[Spart]

I’ve been doing some research and it seems like there are pros and cons to both 0w and 5w — and that a perfect middle ground is 0w30

0w provides for better protection on cold starts, less friction which results in no power loss (losses of upwards of 5hp for 5w) and faster cooling. and moving up to 30 will provide better at-temp protection. and there are certain 0w oils that hold up well and don’t sheer much. let me know if any of this checks out lol

I run 0W-40 and it will sheer down (verified by UOA testing) to just above the 0W-30 range, but without giving me any grief on cold starts.

There's not a huge argument to be made against 0W-40 or 0W-30 vs. the US spec 0W-20 - the additives just need to be right for the particular engine. Our engines call for API SN.

Viscosity used to be treated on a case-by-case basis in US owner's manuals until the EPA got involved and CAFE stopped meaning a place you get a tea and sandwich. Look at most any 90's owner's manual, and you will see a wide range of weights and the acceptable ambient temperatures to use each in.

Hard use (more heat) will indicate a higher viscosity - whether that's from towing or track driving.

0W-40 didn't exist in the early 90's, but it ticks almost every box.

What's extremely funny to me is that the legacy of the ambient temperature and viscosity chart is still with us, but due to EPA requirements, they are not allowed to recommend an oil thinner than that used for CAFE certification. Here's what's in our manual:

What even is the point of specifying a temperature range if there's only one option?

Well, they used to look like this:

Now the temperature chart in our manual makes sense. CAFE killed sense in oil selection.

 

[Noize]

I run Liqui Moly Top Tec 4210 0w30 for everything in my FL5. I think it's a great all around compromise. I don't want to kowtow to CAFE and run that 0w20 water on track or aggressive street driving. 0w30 pours so much thicker, and feels more like what I've been accustomed to in high demand (RPM and boost) four cylinder engines over the years.

All that said, engine tolerances are different and designed for modern oil these days. Overseas cars with the same engines that can use a 30 weight is really illuminating on what is ok.

To me, the biggest concern with oil in these cars is getting capacities right from the stupid plastic clip on the dipstick. A third party dealer did my first oil change at 5k, and there was a slight idle issue when the A/C was on. After lots of investigation, it was overfilled by 3/4 of a quart! I drained, went to the oil at the top of my reply with the correct amount, and the idle issue has resolved completely.

 

[Spart]

Here's something that should really drive the point home. This is the oil viscosity chart for a 2GR-FKS in the US:

And now the chart for the same engine in Australia:

 

[chopsuey34]

OP, stop overthinking things, trust me, there are no objective answers for oil questions. Bob Is The Oil Guy, Motor Oil Geek, they don't have the objective and statistical methods to prove what is truly better. If you track your car, step up the oil weight and change more frequently, if not, stay stock like J_D said.

BTW, per Savage Geese and Limit+1 & Engineering Explained, 0W30 will be thinner at high temps than 5W30 because the friction modifiers needed to get to 0W will sheer at higher temps. Just food for thought.

Savage Geese & Limit+1 ()
Engineering Explained ()

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