Iridium Spark Plugs

Have to agree about claimed increase in performance & economy. There is none!
I only use them because both my vehicles are such a pain to change the plugs so changing them less often works for me.

Oil is a completely different story....running a good quality oil can make a considerable difference both in the long and the short term.

The problem with oil is, price and quality are not linked.....I buy a top shlef oil by the 20 litre and it costs me $4.25 a litre, you can pay twice 3 times or even 4 times as much for an oil that is inferiour, in a retail bottle.

The notion that any spark plug can make a motor go better is plainly rediculous.......

If long term reliability and durability are an issue for you, the value may be there.

I remain gob smacked that any car manufacturer would put so little thaught into a car that access to spark plugs was not straight forward.

What is even more gob smacking, is that a car manufacturer would fit 3 funky spark plugs to the ones that are not accessable and install inferiour ones to the ones that where......what cheap scates

cheers

Agree with olcoolone re performance in a standard road car, maybe a bit of a gain in some high performance application. As far as longevity goes how long do you want plugs to last? I just changed the plugs and HT leads in our V6 Dunnydore...I can't feel much difference in performance or starting. The plugs that came out had a gap of around half as much again as they were supposed to have and the electrodes were badly eaten away so they certainly needed changing. That set were in the car for 110,000 k's and if it had been an old carby non computor controlled engine probably would have been very hard to start and gobbled fuel like there was no tomorrow....that's if it ran at all lol.
We had a sales rep that called in now and again to our repair shop and had just picked up his Bitsaremissing V6 from a service. He had looked at the invoice and asked us why they had changed 3 plugs as he knew it was a V6. We told him that story about the standard type plugs in the front bank of cylinders and the platinum ones in the rear because you had to dismantle half the engine to get to them. (:-))
And yeah definetly lube the threads

Cheers
Pop

If you can show me real proof that any of the main stream oils are better than another I would love to see it.

Even cheap oils will exceed the capabilities and quality most vehicles need.

But if it makes you feel better use a better oil.

Most people will not be able to tell the advantages as so many other factors come into play.

Oil companies would love you to think different.

How do you know the oil you're using is the best and have you done any intensive research of other brands and were they done under controlled conditions.... do you get your oil analysed at each oil change?

Bit like buying $300 Nikes when you only want them to bum around the house in.... they make you feel special.

Oh and
"What is even more gob smacking, is that a car manufacturer would fit 3 funky spark plugs to the ones that are not accessable and install inferiour ones to the ones that where......what cheap scates "

$10.00 savings per car over 1 million cars is not a small amount.

Yes I have researched it.

The first thing to look at is the specifications the oil meets or exceeds, and then who actually guarantees the oil meets those specifications.

Knowing a little about oil chemistry and what is done to achieve certain things and knowing a little about the oil specs, helps

Secondly you can make some simple observations, such as the amount of sludge on the interiour of the engine.

Sticking ya finger in the oil filler and seeing what comes out is a start, or looking at the underside of the rocker cover and observing the amount of sludge or varnish there.
Looking at the oil when you drain it and having a scrape of the bottom of the sump while you have the plug out.

making observations of engines at the time of reconditioning

And of course the sceptics will poo poo the fact that changing to a good quality correctly selected oil can improve the performance of engines over time...actually over a quite short time.

Trusting independent testing of oils.

Persoanlly I use a diesel spec oil, in all my engines.

Main stream retail oils probably do not get the scrutiny that diesel spec oils get. there are not single users that consume the huge volumes or have the testing facilities for main stream oils like there are with diesel spec oils.

I am not talking main stream retail oils, I view them mostly as wasted money.

There are many people who will testify to improvements when changing to the 3 specified and proven diesel spec oils from over priced retail oils.

The transport industry uses these oils in massive volumes and those that use them have very large sums of money invested in their engines.......these people do analise and test...if the oils do not do the job they simply don't sell.

Those top 3 oils are mobil devlac, caltex dello and shell rimular...there is very little to seperate them and they all meet the same group of specifications and they are all mixed fleet oils that will run happily in diesel and petrol engines. They are all made and guaranteed to the same specification worldwide.

It is very common for people to post on forums when they are having problems with their older toyotas, blowing smoke and using oil after changing to some funky retail oil.
When they change back to one of the popular 15w40 diesel spec oils the problem goes away.

Most of the issues with oil will not be the friction and wear issues the advertising goes on with. it will be sludging due to the oil breaking down with heat and it failing to clean and suspend solids.

A chealpy made oil...not necessarily cheap to buy will be made of inferiour base oils and will rely on viscosity modifiers to achieve its spec.

these cheaply made oils will not maintain specification or performence anywhere near as long as a quality oil.

They will break down and produce sludge and varnish, not maintain viscosity and will not adequately suspend meterial so it can be dealt with by the filter.

result sludge and franish on the inside of the motor, sediment in the bottom of the sump, a PCV tract that is not clean and may be blocked..and so forth.

I used to be a fancy retail oil man...since changing to diesel spec oils I have personally observed my engines are significantly cleaner inside and there are lots of niggly little problems that simply don't occur any more.

there are many who have doe the same and will testify the same.

AND we are all paying a hell of a lot less for our oil.

olcoolone......mate I think we are probalby singing from the same song book......just a different rendition.

Those who sell retail oil have been having a lend of us for a very long time.

cheers

Geltleman, we may be getting a little off topic with oils but from my point of view (retired mechanic) I found that the change intervals were far more important than the brand. Also what a lot of people neglect is that the vehicle maker usually specifies a change point for oils based on distance, time and operating cycle. Most don't read the fine print where the change point is for "normal" (whatever the hell that is) and down to half that for "extreme' operating conditions.
Personally I have always asked owners how long they intend keeping a car when they ask "how long before the next service." If like most you intend changing the car every 2-5 years and around 100,000 to 120,000 ks Most common oils are just fine as long as they meet the specs of the car maker.
If you are going to keep it until it dies of old age, or you have fallen in love with it then the use of the best oil you can get is warranted.

Cheers
Pop