Inexpensive motor oil

I have been using Valvoline VR1 20w50 in my XK120, for which I just paid $3.50/qt by buying a case of three 5qt containers (Amazon). This is half of what I paid last year when I bought cases of quarts.

I just noticed another quality oil for even less:
Castrol 03112 GTX High Mileage 20W-50 Synthetic Blend Motor Oil, 5 Quart for UNDER $3/qt (Amazon).

Given how much oil our car’s need per change(12-14), I’m delighted by the new lower prices.


I’m not an expert on the subject of lubrication but I understood that we shouldn’t use these modern (read high dope content/ additives or even synthetic) oils in our old XK engines. More in particular, using these oils in the gearbox (which uses the same type of oil as the engine) will lead to all sort of problems and can be very “expensive” (instead of saving cost). I’m afraid that the oils you refer to are typical examples of such “modern” oils. There are plenty of these “Classic” oils from many different brands and as competition between them is increasing, prices are getting better.

Bob K.

So long as the ZDDP content is sufficient, it’ll work fine.

These modern formulations all have enough

Here is one data point

Last weekend I was racing with some pals. The car’s are all 1974 and older, and all run vintage motors (no modern LS or coyote crate motors). Our pistons and valves are modern and some run steel cranks and modern forged race rods. One of the guys, Bob, blew a head gasket at the end of the first day. He is the sort of guy who then says, “I’ll install a new one after dinner.” He is 10x above me in knowledge and experience.

Since there was plenty of time we kicked back and talked about oil. I asked him about his experience using Mobil 1 (15w50) in his nearly 50 year old European twin cam motor.

It was his experience that even the old style motors do better on modern type oils (with enough ZDDP) due to the advantages of the vastly better temperature and wear stability and their higher wear protection. He also said yes they can leak a bit more on old motors because they don’t start to thicker and sludge up fast like conventional oils. We all run modern seals where possible and catch cams on our race cars to keep the track clean.

Anyway, if I could get a full synthetic 20w50 with zddp for $3/qt, I’d be using it over conventional oil. I might not be right. It’s just another opinion.


VR1 20w50 for $3.50/qt! Thanks.
Many air cooled Porsche guys swear by this…and BradPenn 20w50 (which is a quantum leap more expensive than $3.50).

I use Brad Penn partial synthetic in my twin cam race engine. No lube wear failures in 5 years. Good stuff but it’s $8/quart.

My oil temps never go above 210F (eg I’m not that fast). So a conventional oil should be ok. Some
Oder. Race motors run hotter, and this is one place you can see synthetics clearly have superior thermal stability.


Back when I first purchased my XK I used Castrol 30 regular exclusively, however, with the concern regarding zddp I switched to Kendall GT-1 20W50. I purchase it a case of 12 at a time (plus an extra) and even with a discount of 10% it works out to $5.70 Cdn./946ml ($4.31 U.S.) plus a total of $2.2l Cdn. “environmental handling charge” on the order. Ironically, the outfit I buy my oil from is the same one I used to purchase my Castrol from back in the day. I have never had any problems with the Kendall, although I grant you I am not getting the car up to the redline, merely enjoying cruising at 55-65 mph in my dotage! The car holds a steady 60psi at 3,000 rpm (engine rebuild 10 years ago), doesn’t burn oil and, after years of using silicone, doesn’t experience any substantial leaks. The worst leakage (topping up every 3,000 miles) used to be from the gearbox (30W regular), but since the rebuild by Vintage Jag Works this summer even that is now as dry as a bone. As they say about a certain fast food, “I’m loving it”!


I spent 2 grand on my gearbox rebuild and it still leaks. Must have sent it to the wrong guy.

I used Kendall 20w50 for years because it
(1) wasn’t Penzoil
(2) was reasonably priced.

But at $3 to $3.50 a quart I can be a Valvoline/Castrol guy and save $. Plus the Valvoline 5 qt jug has a really nice no drip pouring spout.

There was a TV ad on several decades ago… It advertised a brand of oil filter… In the 30 sec. spot, it hit the highlights of “their” quality and the competitors “non-quality” oil filter… I’d bet the tag line will ring a bell for most… it was simply:
Pay me now, Or pay me later"…
I’ve used Castrol XL 20w40 since the mid '60’s… When Castrol “dropped” the “XL 20w40” in favor of the “GTX 20w50”, they ALSO reduced the ZDDP in the oil (from a quantity suitable for pre-emission cars)… So, I started adding the ZDDP… Several years ago, I “found” a place in the Pacific Northwest that carries the “Made In England” Castrol XL in 20w50. It has the 1970 ZDDP level. I order three-four “Five Liter Tins” at a whack… not cheap, but then, I don’t have ANY “cheap cars”!!
Ya gotta cheap car?? Buy cheap oil!!!
Charles Ch# 677556.