I Ditched Mobil 1 EP for Castrol EP & This IMMEDIATELY Happened

The first brand of engine oil I used was Mobil XHP (conventional mineral tech – not to be confused with Mobil 1). Those were the years when I drove German classics.

Mobil served the older engines without doubt, and I stuck with them all through my time with the older German machines.

My OCI with this oil type was three months – or 2,000 miles, whichever was first. For the age of the engines and my driving conditions, this was all that was demanded, and it worked flawlessly.

Then, I switched over to modern Japanese engines, requiring a lighter weight. With relatively low miles and reduced driving, my taste in engine oils also changed: that was when I decided on Mobil 1, after extensive research.

Mobil 1

The first Mobil 1 gallon I ever turned into a Jap mobile was the regular oil spec – without the extended performance advantage. On the gallon, it was rated as being good for six months or 5k miles, whichever came first.

Coming from 3-month OCIs (or 2k miles), this appeared to be AWFULLY long – and I shortened the time down to about 5 months (I didn’t bother about the miles since there was no way I’d cover that much in the span, given my reduced diving).

I was happy to change the oil in this manner; the engine was happy, and ultimately, my mechanic then (I hadn’t yet answered the auto DIY call) was also happy.

Why change what makes virtually everyone/thing happy?

Then, it became extremely difficult to get Mobil 1 engine oil locally (I was overseas at the time), and ultimately, I needed to ship my oil in.

That was when it suddenly made no sense again.

Mobil 1 Extended Performance & Filters

Shipping engine oil from Europe or America to Africa wasn’t the most economical use of my hard-earned money. To worsen issues, my wife and I both had daily drivers, which made it two vehicles that periodically needed to be serviced.

That was when I thought hard and decided against the regular Mobil 1; ‘Extended Performance’ it was going to be.

Mobil 1 Extended Performance promised 20k miles or a year of service: whichever was first. Since I wasn’t driving even 5k miles a year, I simply needed to keep the engine oil for a year in the sump and all would be good.

However, reading the fine print, I understood that I’d need to also buy special long-drain oil filters for the extended drain since I would be effectively going ‘heavy duty’.

I ordered the first batch of 5W30 Mobil 1 Extended Performance engine oil and also bought special extended drain oil filters to match.

I took things the extra patch and bought a set of oil filters, each for the vehicles my family owned then. In essence, instead of running one oil filter, I ran two, changing the first after six months and allowing the next to run until the end of the 12th month.

However, when the year had run its course, it was time to change the oil (and the last batch of filters), I noticed that there was little difference between the color of the oil coming out from the sump and that which was trapped in the oil filter.

This was unacceptable to me, especially given that I had taken all manner of precautions to make sure that I got ONLY fresh oil circulating in the system.

Undeterred by this ‘experiment’, I decided to opt for a change of filters, before condemning the idea of extended drain altogether.

A Change of Filters

I was back to research, and Fram popped up. I picked up the Fram Ultra Synthetic for its extended drain property and ordered two units for both vehicles.

Now, instead of running all Mobil 1, oil and filter, I was running Mobil 1 extended drain while running extended performance Fram oil filters.

When I changed the engine oil at the end of the following year, the oil the filters held was noticeably darker than what came out of the sump.

I was positive, now, that the oil filter was doing its job – properly (in extended drain capacity).

I retained it and have been using Fram Ultra Synthetic Oil filters to this day.

However, there was an ‘accident’ that caused a slight change in this setup. This ‘accident’ became the basis of today’s article.

The ‘Accident’ That Was Castrol

The vehicles were due for an oil change and for some strange reason, the Mobil 1 official store on Amazon (my preferred online store for engine oil at that time), didn’t stock it.

I delayed for close to a month, running an OCI of 13 months, just to see if there would be a restock.

Nothing.

Into research I went again, and that was when I came across Castrol Edge Extended Performance.

The engine oil promised similar drain interval/protection to what Mobil 1 offered, and folks who had used it had no complaints.

I delved in and placed an order.

Effectively, that was how I moved from both Mobil 1 engine oil and oil filter, switching over completely to Castrol and Fram.

Discovery

Mobil 1 served me brilliantly while I used it and I had no complaints. I strongly suspect it would still be powering my engines and resting in my sumps were it not for the out-of-stock scenario I encountered and had to switch.

However, there was something that had become noticeable during my days with Mobil 1: after sustained highway speeds, especially during inter-state travels, I usually burnt some engine oil. This oil burn wasn’t usually much but it was always enough to become clear on the dipstick.

This shortage, wasn’t enough to warrant a top-up, before the end of the 12th month though, so I simply shrugged it off.

With Castrol Edge Extended Performace, I noticed something unique: I did the regular interstate journey to the same destination I have always done with the vehicle.

Guess what?

I checked the dipstick after I arrived and was impressed: there was no visible oil burn at all. Now running close to a year and the final change, the engine oil has not only remained super clean, it’s also at the same spot on the dipstick as it was when I first put it in, more than 8 months ago (I have not also changed filters this cycle at the sixth month).

Mobil 1 vs Castrol: Going Forward…

Mobil 1 and Castrol are both great engine oils, no doubt, and I have absolutely no regrets using Mobil 1 for the applications I did.

However, I discovered that with the 3MZ-FE in the Lexus ES330, Mobil 1 burnt (during interstate journeys) while the Castrol Edge I used later did not. It somehow also managed to remain cleaner in the vehicle when compared to Mobil 1.

For these reasons, I won’t be going back to Mobil 1 again. In the sad event that Castrol Edge runs out of stock, I’ll be considering another brand, maybe Valvoline, to see how things pan out.

Who knows? The new brand (should that day come) may just give me reasons to switch yet again.

Perfection is a never-ending game! If in doubt, ask Lexus.

Love the Above? Subscribe for More