Goss' Garage: Oil Viscosity

Pat Goss talks about the all-important slippery stuff; oil.
Find us on your TV @ www.motorweek.org/about/statio...

[@elguille989]

My dad owns a z24 cavalier, the user manual clearly recommends 5/10w30, well he used 20w50 and on a 17 year old LD9 engine, guess what happened? First of all, he used a cheap conventional oil, second of all he didn't change it for 5 months. All timing chain parts except the sprockets where destroyed, the chain(6 years old) survived but was very stretched, this lead to the car to bent 6 valves. Rod bearings burned and the engine all gunked up. Still the mechanic who fixed it, told him because here (Venezuela) have a hot weather (Between 85 and 95) we should use a thicker oil, no less than 10w40. He also said that because new rings and bearings we should get a thicker oil. So I told my dad, yes, because this Chevrolet wasn't designed for a hot summer day in Texas right? Chevrolet says in the user manual a 5w30 will protect your engine over 100 degrees. Finally dad trusted me and we used what we could find, a cheap synthetic 5W30, the engine is very lively right now. Gonna change the filter in the next month just in case it got clogged. Thanks for your guidance Pat.

[@ba851]

Good lord, how many years has Goss been holding down the fort now?! A true legend. Good to see him still in the game.

[@1013VS]

HT Bob I can see some hesitation but still going strong

[@ba851]

Naiyo I've been watching motorweek and listening to Goss's tips since I was a kid, and I'm 46 now.

[@ba851]

Joe Johnson don't be a hater towards American automotive history. Motorweek has withstood the tests of time. Many have come and gone, but Motorweek had the winning formula from the beginning!

[@landyachtfan79]

Almost 40 years now!!!!!!!

[@robertmontgomery7158]

The crud is from lack of oil changes, not from viscosity

[@rjolly87]

He never mentioned anything about going the other way. I noticed a lot of preignition and oil consumption issues on my car for the last couple of years. Given the old thing has 200k miles on it, figured it was nearing end of life. Then I discovered my oil change place has been putting in 5w20, despite it requiring 10w30. Next change it was filled with synthetic 10w30, and many of the issues went away. The advice is sound however, stick to what the manufacturer recommends

[@JBaek24]

My S2000 recommends 10w30 from Honda but since the vehicle sits for a long time (driven once or twice a month), I put in 0w30 to help get the oil to circulate as quickly as possible at first cold start up to reduce wear. 10w30 makes sense at the track or constant normal driving but not for my specific situation. Agree?

[@hamad915_]

Jae Baek sure

[@Hubjeep]

Modern Syn. oil is more "shear stable" (ability to resist viscosity change) than older oils. S2000 (unique engine designed 20+ years ago) revs to 9,000 RPM. Considering a conventional oil may be used, Honda may have (20 yrs ago) wanted to spec 10w since they were more shear-stable than a 5w. Today a synthetic 0w-30 is good to go.

[@SantanKGhey1234]

Jae Baek I store my 2001 S2000 with any cheap 10W30, then when spring comes I run 0W40 M1 Euro.... For the street and also very suitable for the track, you should run at least 40wt on the track... Love my s2k!!

[@shopwithaaron]

Just got my 2012 Optima serviced for the "metal shavings" recall and they wanted to flush the brake line.....only 51,000 miles? Is it time?? Thx!

[@thevinceberry]

Test the brake fluid to see if it is too acidic or not. 50,000 miles on normal driving sounds about right.

[@schift320]

There is NO correlation between deposits and oil viscosity. Deposits are polymers that have formed due to poor base stock or poor additives.

[@topgunns1000]

I don't know how some of you people think you know more than the engine manufacturer. Just follow what's in the manual.

[@captiantim1]

also thicker oil ,makes gas mileage lower. more residents in the engine, pat is aways right

[@alexvieira7945]

Thicker oil will also affect fuel economy 🚗⛽

[@Jesus-bmw]

How about putting thicker oil and older engines

[@BlettzaHrekleW]

2nd number in oil is what really matters. So in say a 5w-30 oil , a 10w-30 oil will be exactly the same at operating temps. The 2nd number is the operating temp rating. 1st is your cold flow rating so whether 0 , 5 ,10w-30 oil its all the same at operating temps only diff would be at cold temp start ups the 0 would be better for colder climates

[@animal16365]

One question. Say your vehicle calls for 0w20. You check your oil and see that it needs a quart. You check the station your at and realise the y only carry 5w20 as the lowest oil type. Could you use it in a pinch or should you keep going until you come to either a dealership or auto parts store??

[@francismartinez6049]

animal16365 I would think it would be fine. Same thing goes for gasoline. Say your car requires premium fuel and for some odd reason there is only a lower octane gas available, you can use it in a pinch. There is some wiggle room for tolerance

[@XenomorphLV426]

Use distilled water, change it asap.

[@thevinceberry]

That's fine. your engine will stay warm and the oil will be at 20 grade.

[@averyalexander2303]

Yup, topping off with a slightly different viscosity oil than what is recommended is perfectly fine and is definitely better than continuing to drive with low oil. Keeping an extra quart of the proper oil in the trunk isn't a bad idea though, especially if your vehicle requires occasional top offs.

[@anibalbabilonia1867]

Agree!

[@s.h.5726]

Good tips Goss. My cars manufacturer says I can change at 3750miles or more but then the dealership tells me to change it every 3000 miles. I have seen some people complaining about oil sludge causing engine problems even with proper oil change intervals, so it sounds like even proper maintenance with not so good engine design an cause problems. I'm sure all the 2.7L V6 dodge owners know what I'm talking about.

[@bostar7770]

Nowadays vehicles are very efficient, so is it still recommended to change your car oil every 3,000 miles with the use of either Mobil or Castrol synthetic oil? Can we change the oil every 4,000 or 5,000 miles instead?

[@Tool0GT92]

Follow what your owners manual says. Most newer cars go around 10K miles on full synthetic and you will be fine, just make sure you keep an eye on the level during that time. Since I'm OCD about oil, I change it around 5k.

[@francismartinez6049]

Bo Bu doesn't matter what brand of oil you use as long as it's the right viscosity . You can buy the cheapest oil at Walmart and it would work perfectly fine.

[@rmwarriors16]

I would go with the manufacture recommended oil viscosity and change interval under severe condition. You also need to know what conditions are you putting the oil thru. For example, if your tracking or racing the car under harsh punishment, or live on a dusty farm with no paved roads then I would check the oil level and change the oil more frequently and replace engine oil more often. The only car maker I would not follow is BMW. Their 15K mile and engine oil and oil filter change is ridiculous . I have seen all of my BMW with that oil change interval have lots of crude inside the oil cap, valve cover etc. Plus all the oil leaks because of the acidic oil eating the seals away etc.

[@bostar7770]

Thank you all for your feedback. I guess I will drive it up to 5K and then change my oil. And my car is a 2016 Nissan Murano and I’m using the Mobil 5W20 Synthetic oil.

[@georgeparker555]

Bo Bu I don't like going over 7k with synthetic oil. I'm very OCD and change it every 5k miles which is playing it safe. Make sure you get a good oil filter which is critical

[@joshuasamms8531]

Thanks Gross!!!

[@MrHarbinged]

just change your oil before the color changes too dark..

[@silverioarroyo5968]

Is it ok to go from 5w30 in summer down to 5w20 for winter and vice versa, I just use 5w20 full synthetic year round.

[@thevinceberry]

Follow whatever your owners manual tells you. I think you misunderstand about engine oil. Changing from a 30 grade to 20 will increase fuel economy by a little but also hurt your engine.

[@chadharmon5716]

If you have a lot of miles on your car running a start up grade higher then recommend is not going to hurt anything but I would still with the same running weight say 5w30 vs 10w30

[@HackHunter1835]

That valve cover has to be from that POS Chrysler 2.7 engine lol

[@ozzstars_cars]

Engine oil is a hot topic. Should be lots of opinions on this. I posted an oil change vid on my channel and the hornets nest started stirring!

[@dsteffler54]

Wrong on a few points..:: lower viscosity and higher flow rate many mean better cooling but not necessarily less wear due to lower film strength.... and sludge formation isn’t caused by using a higher viscosity than recommended.