I changed my oil about a month ago and was cleaning out the garage. I came across the old bottle and was shocked to read that it said "syntec BLEND". I e-mailed Castrol and they said to change it at 3,000 miles or 3 months. Why would they make a syntec blend if it offers nothing but a higher price tag? Their packaging was confusing: it was almost exactly the same as the full syntec oil and the same color. Can I stretch this to 5,000 miles if it's 50/50 syntec? Has anyone used the blend before? Isn't the 3,000-mile change really just for cars from the 70s because they're harder on the oil? I've frequently run my old Cherokee (I don't have the Jeep anymore) past 4,000 miles with dino juice oil and have never had engine problems with it.

 

because they can... Same thing with Castrol. Basically the synthetic blends were to get your money, without giving you protection. I'd do an oil change at a relatively short duration, and go back to full synthetic.

Engines now are actually harder on oil. Especially boosted engines (turbo or SC) that generate lots more heat per unit displacement. Engines also seem to be set to run a bit hotter for some emissions reasons as well.

Matt

 

I think only German made Castrol remain full synthetic, but I only use Redline Synth.

 

Mobil 1 is full synthetic too. This is from the Mobil 1 website:

Is Mobil 1 with SuperSyn Technology a fully synthetic motor oil?
Yes, it is. To meet the demanding requirements of today's specifications (and our customers' expectations), Mobil 1 with SuperSyn uses high-performance fluids, including polyalphaolefins (PAOs), along with a proprietary system of additives. Each Mobil 1 with SuperSyn viscosity grade uses a unique combination of synthetic fluids and selected additives in order to tailor the viscosity grade to its specific application.

But the bottom line for me is either Castrol Euro, Mobil 1, Royal Purple or Redline will be fine with reasonable change intervals. Artoo gets a change every 5000 miles.

Rich

 

Funny you brought this up.

There are some basic differences between synthetics oils such as PAO oil versus Polyol Ester oil. Polyol Ester oil like Redline is supposed to be better at higher temperatures with better resistence to breakdown which is superior for turbos in high rev situations. Polyol Ester oils require much less additives to provide multigrade protection which accounts for its stability. I think Castrol, Mini oil are similar to Mobil 1 in that they are super refined mineral oil or PAO. Poloyol Ester oils are synthetically recreated using ester bonds. While PAO oil is legally full synthetic, it is still a mineral oil.

That is why after 20+ years, I would still use Redline 5W30 oil for the summer (and track season) even though it is not A3 or Mini approved.

 

You don't say what year your MINI is, but I assume it 2nd Generation (2007+). If so, I would change it immediately. "Synthetic blend" means it doesn't meet the standards required to call it full synthetic. Probably a step up from traditional natural oil, but up to "full synthetic" standards. MINI's require full synthetic, and should have an oil that meets a fairly strict standard within the "full synthetic" standard.

Use either MINI branded 5W-30, Castrol Edge 0W-30 (don't use Edge 5W-30), or use one of the oils recommended by MINIUSA:

 

I think that the suggestion to change it IMMEDIATLY is a bit of an over-reaction. The dino oil will be fine for a much shorter service interval than the synthetic.

Sure, it's not as good in the extremes, but it will work. Many a motor car (and even race car) survived just fine on non-synthetic oils.

Matt

 

And thus why I stick with Mobil 1. Castrol I think is more concerned with their marketing campaign than their oil.

 

Castol Syntec 0W-30 oil is an excellent choice for our engines. I am using this oil for my MCS which I have been taking to the race track. I had used oil samples from my engine analyzed few times. The lab reports are showing that this oil is doing a superior job of minimizing engine wear, even under hard track driving conditions. I am sticking with this oil!

 

That might be true for a 1965 Mustang, but I'm not sure it is for a direct injection, high compression (and possibly turbocharged) engine that is designed for an oil with a specific viscosity at temp and shear strength. Perhaps if never takes it above 2,500 rpm...

 

(very) high temp stability, and longevity. To get to the place where the high temps will make a difference, you have to be close to overheating your car. Longevity can be dealt with by not running the oil for 10k+ miles.

The service grade is more what is of concern for the short term.

And the OP didn't use pure dino oil, but a synthetic blend.

Matt

ps, the car in my sig may be a 65 Mustang, but it's' got a FI 302 in it based on a SSV 5.0 out of a highway patrol car! It's seen track duty, and runs Red-Line oils.

 

+ 1 ^

Run it for a short change interval & change to the correct stuff. The sky is not falling & your engine will be OK.

Now that's thinking with your dipstick Pinky.

 

The problem with synthetic "blends" is that you can't tell how much synthetic vs. regular oil you're getting. Is it 50%-50%? 90%-10%, 99%-1%. No one knows, and the manufacturers apparently want to keep it that way.

 

... That's funny! BTW, I love that Castrol commerical!