Engine oil

[fixitflav]

For a few years I've been using Halfords part-synthetic oil, and it's been OK AFAIK.
But I just went there to buy 5 litre for an upcoming change, and they've complicated things. It was all either fully-synthetic or didn't say which. Any idea what's going on? Is fully-synthetic worth the extra? At my time of life I drive with the utmost circumcision, as Arthur Daley might put it.

 

[Burnerman]

Usually a semi synthetic oil is perfectly good enough, but this can depend on the oil change interval, some of which are crazily long. Diesel engines also play a part in this to some degree.
It’s vital to use the correct grade in wet belt engines, and also hybrids.
Some engines actually suffer bore glaze when using fully synthetics which results in oil burning.
A motor factor will tell you what your choices are.
John

 

[carmanmemoranda]

Theres a lot more to oil than fully synthetic, semi synthetic or non synthetic.

Get the right grade for the engine. Quality, then viscosity, then type.

What car is it? Then it may be possible to advise if the specified oil is ultra important, or not so.

 

[fixitflav]

Usually a semi synthetic oil is perfectly good enough, but this can depend on the oil change interval, some of which are crazily long. Diesel engines also play a part in this to some degree.
It’s vital to use the correct grade in wet belt engines, and also hybrids.
Some engines actually suffer bore glaze when using fully synthetics which results in oil burning.
A motor factor will tell you what your choices are.
John

Thanks for that. I can source some part-synthetic so I'll go with that. It's a petrol, recommended change at 6000 miles or 12 months, due about now.

 

[fixitflav]

Theres a lot more to oil than fully synthetic, semi synthetic or non synthetic.

Get the right grade for the engine. Quality, then viscosity, then type.

What car is it? Then it may be possible to advise if the specified oil is ultra important, or not so.

Thanks, it's a Hundai i30 petrol. Handbook recommends Shell Helix Ultra AH-E W-30, or Helix Ultra 5W-40 but it doesn't say under what circs to use one or the other! And it doesn't mention part or fully synthetic. I'll stick with part.

 

[carmanmemoranda]

It's not what i would call an ultra critical engine.

From memory i think Comma reccomend Syner Z fully, 5/30

commoil.com

put in your reg

 

[Astra99]

The Hyundai I30 and the Kia Cee'd both use the same engine. The Cee'd specifies a 5W-30 fully synthetic oil for the UK climate, so I would suggest this is also suitable for your Hyundai I30. HTH

 

[Burnerman]

Maybe the oil recommendations depend on the finishing or coating on the cylinders......
Example - Kawasaki Ninja 400 four cylinder engine that can rev up to 17000 rpm ( imagine that)! 10/40 semi synthetic recommended.
My own Honda Blackbirds (1137cc, 168 BHP, 10500 rpm) the same brew. Fully synthetic definitely not recommended as the cylinder bores glaze.
John

 

[JohnD]

it's a Hundai i30 petrol

The age of the engine design is important. I've had vehicles that were designed and built long before synthetic oils came on the family car market.

Synthetics allow engines to do more mileage before needing a change, but with regular changes you should not be exceeding the working life of whatever oil you use. Changing on schedule is more important that high-priced oil.

 

[JohnD]

Where I live, Mobil is the best value of the big brands.

I look up the recommendation on https://www.mobil.co.uk/en-gb/engine-oil

And I check that it meets the manufacturer's specification in the handbook.

I think all the manufacturers provide recommendations, they tend to guide you towards their most expensive products but show others as acceptable alternatives.

The supermarkets and sheds often carry own-brands badged for them by major oil companies, in the more popular grades.

 

[norseman]

The age of the engine design is important. I've had vehicles that were designed and built long before synthetic oils came on the family car market.

Synthetics allow engines to do more mileage before needing a change, but with regular changes you should not be exceeding the working life of whatever oil you use. Changing on schedule is more important that high-priced oil.

+ 1
The car manuf. spec. for the engine oil is far more important than the label or the price. I use a 5w40 fully synthetic in my old BMW but stick to a 20w50 with high zddp for the old Range Rover as it's flat tappet engine design harks back to the 1960's

 

[fixitflav]

Thanks gents for your comments

 

[Harry Bloomfield]

+ 1
The car manuf. spec. for the engine oil is far more important than the label or the price. I use a 5w40 fully synthetic in my old BMW but stick to a 20w50 with high zddp for the old Range Rover as it's flat tappet engine design harks back to the 1960's

That is exactly what I have always done - each vehicle manufacturer, sets a a spec. for the oil, just note the spec., and find a match from a reputable company. I buy it in bulk, 20 or 25L at a time, which saves even more on the cost. It takes near 7L per change, so otherwise, that would be a 5L, plus part of a second 5L. 20/25L just works better.

 

[Mottie]

It annoys me when they sell oil in 4ltr cans. It’s never enough for most cars and a single litre can is about half the price of a 4ltr can. Our A3 is supposed to take 3.6 litres. 4ltrs is never enough though.

Maybe I need a longer dipstick……

 

[fixitflav]

It annoys me when they sell oil in 4ltr cans.

Agreed. I don't buy it