There's no definitive answer.Much is down to personal choice. Try the search facility for a few days of reading on the topic. If you want some opinions, post some details of your car age model mods driving style how regularly you change it etc.

 

I'd go for a 5/40 Fully synthetic this time of year. Your choice of brand, dependant on budget. Silkolene Pro S at the moment. In the New Year changing to Optima Vimax from EXOL oils. Bob

 

i use millers

 

Any API (not the tuning company) spec Oil.

I use a 15/40 semi synth and has been fine in mine with 450bhp+

There's alot of rubbsih spoken about oil. If you don't want to do oil changes regularly and by regularly I mean every couple of months then I'd say use mobile 1 15/50.

It costs me £20 to do a full change including filter. It takes me half an hour.
Therefore I do it every couple of months and have no problems whatsoever.

 

Motul

 

Must admit I was going to ask the same question re the oil situation but it does seem to start a debate on the uses and prices of what you can get as to what you need
Stick to the manufacturers spec of oil if you feel you have to spend 5 times that amount for your own sence of security go for it, unless you are running megga power and the car is running hotter theres no need to deviate from that
Ive seen many engines let go using silly priced oils, for my opinion it just leaves a more expensive stain on the floor

 

Motul 10/40 fully synthetic

Tony

 

Couldn't have put it better myself

 

If it's a 2008 car I believe your handbook recommends 5w-30?

Cheers
Guy

 

Daz why do you use semi and not fully, also the 15/40 you use, what is the brand and do you give your car any beans on 15/40.

cheers

 

At the end of the day it's personal choice and your car........but modding your car or using it on track takes it outside of the manufacturers envelope with regards to oil recommendations.

Step up tha power or the abuse and you need to step up the quality to reduce the risks of potential damage or problems.

I posted this some time ago but it explains why this is the best way to go.

If you are "modding" your car and adding BHP then consider your oil choice carefully as the stock manufacturers recommended oil will not give you the protection that your engine requires.

A standard oil will not be thermally stable enough to cope with higher temperatures without "shearing" meaning that the oil will not give the same protection after a couple of thousand miles as it it when it was new.

Let’s start with the fundamentals. An engine is a device for converting fuel into motive power. Car enthusiasts get so deep into the details they lose sight of this!

To get more power, an engine must be modified such that it converts more fuel per minute into power than it did in standard form. To produce 6.6 million foot-pounds per minute of power (ie 200 BHP) a modern engine will burn about 0.5 litres of fuel per minute.(Equivalent to 18mpg at 120mph). So, to increase this output to 300BHP or 9.9 million foot-pounds per minute it must be modified to burn (in theory) 0.75 litres.
However, fuel efficiency often goes out of the window when power is the only consideration, so the true fuel burn will be rather more than 0.75 litres/min.

That’s the fundamental point, here’s the fundamental problem:

Less than 30% of the fuel (assuming it’s petrol) is converted to all those foot-pounds. The rest is thrown away as waste heat. True, most of it goes down the exhaust, but over 10% has to be eliminated from the engine internals, and the first line of defence is the oil.

More power means a bigger heat elimination problem. Every component runs hotter; For instance, piston crowns and rings will be running at 280-300C instead of a more normal 240-260C, so it is essential that the oil films on cylinder walls provide an efficient heat path to the block casting, and finally to the coolant.

Any breakdown or carbonisation of the oil will restrict the heat transfer area, leading to serious overheating.

A modern synthetic lubricant based on true temperature-resistant synthetics is essential for long-term reliability. At 250C+, a mineral or hydrocracked mineral oil, particularly a 5W/X or 10W/X grade, is surprisingly volatile, and an oil film around this temperature will be severely depleted by evaporation loss.

Back in the 1970s the solution was to use a thick oil, typically 20W/50; in the late 1980s even 10W/60 grades were used. But in modern very high RPM engines with efficient high-delivery oil pumps thick oils waste power, and impede heat transfer in some situations.

A light viscosity good synthetic formulated for severe competition use is the logical and intelligent choice for the 21st century.

Hope this helps at least someone to avoid a catastrophe.

Cheers
Simon

 

The oil I use is an API spec oil that gets changed every couple of months at a total cost of £20 a change (inc filter and crush washer everytime).

As for giving it the beans, it's a bit of a silly question it's 450bhp and has quite a hard life.

I took the engine apart recently to check it before I sold it on and it was mint no signs of wear anywhere!!

Incedently that car was featured in this months Banzai mag Pics were taken last year before it was stripped.

I'm now in the process of building a 600bhp V3 Type R and I shall be using the exact same oil

 

With Simon (it must be the name) on this, Subaru spec 5W30 and it tested on that, so don't waste energy with a thicker oil.

I use Castrol edge 0W30 (so keeping viscosity down cold) long life in mine.

Simon