1976 VW Bus / Kombi - oil recommendation

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Jul 8, 2025
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I have a 1976 Volkswagen Bus / Kombi / Transporter with a stock 2L engine including stock flat tappets (no hydraulic lifters). It’s Australian delivered so it’s dual Solex carburettors and no exhaust gas recirculation equipment. The only modification is an external oil filter and oil cooler. The stock internal oil pressure relief valve and internal oil cooler are still in place. The engine was rebuilt about 10,000 km ago.

I’ve purchased Royal Purple HPS 5W-30. The current oil is Penrite Racing 10; an australian 100% synthetic with about 2000 ppm ZDDP. It’s a 10W-40 and it runs cooler now with the extra oil cooler; between 80 and 95 degrees C (down from 105 to 120 degrees C). I’m getting 45 PSI at 2,500 rpm (70km/hr) which is a bit too much because the oil pressure relief valve starts to open at this pressure and that bypasses the internal oil cooler. So that’s why I’m going to 5W-30. Hopefully about 45 PSI at 4000 rpm (105 km/hr) when oil is 85 deg C.

I’m not worried about the extra cost of high quality. I just want an awesome oil that keeps my engine in great condition. I can only get Amsoil Z-Rod in 1L bottles which is just annoying. And the RP HPS is available in 10W-40 which I may need to use in summer. I can’t buy Mobil 1 Classic 5W-30 in Australia. Penrite has been great, but being a racing oil I’m not sure about detergents for long term use.

Is the RP a mistake?
 
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Have you looked at thesamba.com? I own a 75 Westfalia and it has an1800 motor that I use 20-50 Valvoline and it works fine. I don't have any extra cooler on mine but just the original VW system. When I drive mine on the interstate and stop for gas i can pull the dipstick and touch the oil without it burning my fingers so I guess it is all good. I rebuilt this motor myself about 10 years ago and have put about 30K on it in that time. I don't use synthetic oil in it.
 
Penrite 10-Tenths Racing 10 (10W40) is an excellent oil, 100% PAO and Ester, with lots of zinc for your flat tappets, a strong detergent TBN of 9.8 for long life, and it's API SN for street use. It's a great oil.

Penrite also make a Racing 5 (5W30) PAO & Ester if you want to go a bit thinner.

Another option is Castrol Edge 5W30 A3/B4, this is their European (ACEA) rated 5W30 so it's a thicker 30 grade and has more zinc (ZDDP) than typical fuel economy (ILSAC GF-6) 5W30 grade oils. It's approved for BMW and Mercedes Benz use, and had to pass some very tough tests to get these approvals.

Those other oils you list, Amsoil, Royal Purple, etc are fully imported and very expensive in Australia. They are fine oils, but not worth the extra price. To be honest, even at the same price, I would always select Edge 5W30 A3/B4 or Penrite 10-Tenths over any of the other options that you listed. More expensive doesn't always mean better.
 
Have you ever considered putting a cover over the oil cooler during winter, and removing it over summer when the extra cooling is required? I hear that was a common practice in the past.
 
Have you looked at thesamba.com? I own a 75 Westfalia and it has an1800 motor that I use 20-50 Valvoline and it works fine. I don't have any extra cooler on mine but just the original VW system. When I drive mine on the interstate and stop for gas i can pull the dipstick and touch the oil without it burning my fingers so I guess it is all good. I rebuilt this motor myself about 10 years ago and have put about 30K on it in that time. I don't use synthetic oil in it.
Yes, I’m regularly on thesamba but I don’t find the engine oil advice on there very technically based. I do a few long trips a year and those can include days over 40 deg C whilst cruising on the freeway. The kombi oil slowly gets hotter and hotter the longer you drive. It has an 010 automatic gearbox and I think some of the heat comes from there too. My end goal is to have control over the oil temps and know they’re not going to exceed e.g. 105-110 degrees C on the hottest days. The external cooler has an electric fan to take care of that, but I’d like the fan to not be needed unless day time temp is over 30-35 degrees C. I’m nearly there. As the oil gets hotter, I want the internal cooler to open first, then the thermostat in the remote oil filter housing opens the remote oil cooler, then the fan kicks in.

I also have a concern over the standard filter mount where I’m picking up the oil lines for the remote oil filter/cooler using a spin on filter adaptor. The standard filter mount has an oil filter bypass valve built in, so I need to make sure that’s not opening. I’ve selected an oil filter with its own bypass valve.
 
Penrite 10-Tenths Racing 10 (10W40) is an excellent oil, 100% PAO and Ester, with lots of zinc for your flat tappets, a strong detergent TBN of 9.8 for long life, and it's API SN for street use. It's a great oil.

Penrite also make a Racing 5 (5W30) PAO & Ester if you want to go a bit thinner.

Another option is Castrol Edge 5W30 A3/B4, this is their European (ACEA) rated 5W30 so it's a thicker 30 grade and has more zinc (ZDDP) than typical fuel economy (ILSAC GF-6) 5W30 grade oils. It's approved for BMW and Mercedes Benz use, and had to pass some very tough tests to get these approvals.

Those other oils you list, Amsoil, Royal Purple, etc are fully imported and very expensive in Australia. They are fine oils, but not worth the extra price. To be honest, even at the same price, I would always select Edge 5W30 A3/B4 or Penrite 10-Tenths over any of the other options that you listed. More expensive doesn't always mean better.
I was originally going to use the Penrite Racing 5 (5W-30), but it’s hard to get compared to Racing 10. And then Penrite advised me on their technical forum they would prefer I use the Penrite EDS 10 which has about 1000ppm ZDDP and I’m concerned whether that’s a bit borderline. It’s also not a PAO ester oil, so it’s a step down in my opinion. I guess the HPS may not be PAO ester either, but at least their documentation is supporting suitability for my engine.

Interesting information about Castrol Edge. I started out just trying to go with oil manufacturer’s oil selections from their web sites and choosing a premium option. But that really didn’t work out. I can’t recall Edge being offered by Castrol as a suitable option. I’ll have to check again.
 
Have you ever considered putting a cover over the oil cooler during winter, and removing it over summer when the extra cooling is required? I hear that was a common practice in the past.
Yes I have. But at the moment the oil pressure is too high even by VW’s recommendations which uses 70 deg C as a reference (it’s not the recommended operating temperature I know, but at that temp my pressure is on the high side). So I’m keen to see what a 5W-30 does compared with the recommendations, and it will help with pressure at operating temps too.
 
i also have a 86 Vanagon Westfalia and a 65 VW beetle and I have never had an oil pressure gauge on any of them. I have probably had 14 VW air cooled over the years and My love for them started while I lived in Arizona. My first ones were a 55 Bug and a 59 bus. They both had the 36hp motors and got 30 wt as recommended in the manual. Oil was cheap in those days and came in metal cans.
 
i also have a 86 Vanagon Westfalia and a 65 VW beetle and I have never had an oil pressure gauge on any of them. I have probably had 14 VW air cooled over the years and My love for them started while I lived in Arizona. My first ones were a 55 Bug and a 59 bus. They both had the 36hp motors and got 30 wt as recommended in the manual. Oil was cheap in those days and came in metal cans.
Nice dubs! The 86 would be water cooled yes? And the 65 with a type 1 engine. My 2L is a type 4; they tend to run hot. And I’ve got the full Australian VW Campmobile conversion with auto transmission, so mine runs really hot! To be honest though, this is all just a bit of a hobby. I’m enjoying tinkering with the oil cooling system, testing different scenarios and learning exactly how all the parts work. You see, I’ve got this chronic condition called “engineer” ;)
 
I would personally try Valvoline VR1. High zinc and comes in your desired viscosity. Can go blend or full syn depending on your preferences.
The only Valvoline VR1 we get in Australia is a 10W40 semi-synthetic that is API SJ.

Given API SJ was introduced in 2001, and it's a '76 VW Kombi, it would be better than the original fill of API SD (1971). Followed by some API SE starting in 1979.
 
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I would personally try Valvoline VR1. High zinc and comes in your desired viscosity. Can go blend or full syn depending on your preferences.
I looked at what Valvoline choices were available in local stores a week ago and ended up totally confused. The Valvoline Australia web site product selector offers the Premium Mono 30 as the only option for a 76 Kombi! I know there are many who swear by the mono grades, particularly in the type 1 beetle motors, but that’s not me. I want a modern oil that does a great job. I read somewhere that “racing” oils generally don’t have enough detergents for a daily drive, but I read later that many of the “racing” oils in chain stores do have enough detergents. So that makes the choice uncertain for starters. There were so many different variants of Valvoline oil I ended up giving up.
 
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Penrite 10-Tenths Racing 10 (10W40) is an excellent oil, 100% PAO and Ester, with lots of zinc for your flat tappets, a strong detergent TBN of 9.8 for long life, and it's API SN for street use. It's a great oil.

Penrite also make a Racing 5 (5W30) PAO & Ester if you want to go a bit thinner.

Another option is Castrol Edge 5W30 A3/B4, this is their European (ACEA) rated 5W30 so it's a thicker 30 grade and has more zinc (ZDDP) than typical fuel economy (ILSAC GF-6) 5W30 grade oils. It's approved for BMW and Mercedes Benz use, and had to pass some very tough tests to get these approvals.

Those other oils you list, Amsoil, Royal Purple, etc are fully imported and very expensive in Australia. They are fine oils, but not worth the extra price. To be honest, even at the same price, I would always select Edge 5W30 A3/B4 or Penrite 10-Tenths over any of the other options that you listed. More expensive doesn't always mean better.
I checked the Castrol product selector and it offered only Castrol GTX. Edge is available on their site, but it avoids selecting it. I don’t understand why they would only offer their lowest tier oil.
 
Penrite 10-Tenths Racing 10 (10W40) is an excellent oil, 100% PAO and Ester, with lots of zinc for your flat tappets, a strong detergent TBN of 9.8 for long life, and it's API SN for street use. It's a great oil.
Sorry, what do you mean by “a strong detergent TBN of 9.8…”?

I would be keen to continue using Penrite 10-Tenths if it’s a great oil for the job. I can order the Racing 5 in if needed. I don’t get why Penrite would discourage using this and encourage EDS 10 instead? They had some concern about compatibility with seals was all I could see that made any sense.
 
In its day the Kawasaki 900 4 cylinder motorcycle ran just 8 lbs oil pressure. Briggs and Stratton just use a slinger in the older motors that lasted forever.
 
Oil pressure too high? Is that really an issue?
Yes it is, in this cooling system. When pressure is high, the oil pressure relief valve opens and bypasses the internal oil cooler. As a consequence, the oil will get hotter and hotter until the oil thins out enough for the oil pressure to drop. The minimum ideal oil pressure is 10 PSI per 1000 rpm. I’m getting 20 PSI per 1000rpm. Bypass starts at a little under 50 PSI. At 105 km/hr it’s doing 4000 rpm, so most of the oil is bypassing my internal oil cooler at cruising speed. That’s not ideal! It’s just going to unnecessarily heat the oil up until the bypass valve closes.
 
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