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Mobil 1 0W-40

  Skoda Fabia vRS

ok, i know, oil, not again you all say

but, ive been doin some more readin on it, and this time i decided to have a good look at Mobil 1 0W-40

i requested the data sheets from Mobil and ive got the important viscosity figures, and im very surprised at them to be honest

even though it has a 0W rating, its viscosity at 40c is thicker than that of a 5W-30, and very similar to a 10W-40 !!!

now once its up to temp, its basically the same viscosity as a 10W-40, and based on the figures i have its only a bit thinner than a fully synthetic 20W-50, which would normally be considered a fairly thick oil

so i went out to Halfords today and bought a litre of it, added about 500ml to my car, which is about a sixth of total capacity, i know its not gonna make much difference, but i honestly did feel a difference, my mrs even said about 10 minutes later, that the car seemed smoother, so if she can notice then it must be !

im gonna give it a go on my next oil change, bit worried about oil usage as my car is approachin 90k, but ill see how it goes

just thought i would share my findings with you

based on the data sheet i got from Mobil ive totally changed my ideas on thinner oils, well, in Mobil 1s case anywayz

never mix oils unless you really have to. they can react badly espeical those of different viscosities. higher milage cars are better off with thicker oil due to them being worn. thinner oils can leak
  Skoda Fabia vRS

how would an oil react with another ?

could you share your knowledge on that matter with me as ive never heard anythin about stuff like that in all the stuff ive read an im interested....

ive always read on every oil ive looked at (literally hundreds hehe) that they will fix perfectly fine with any other oil

i think what it says in the handbook is what goes in my car, they dont spend thousands developing and engine and give u the information to keep it running healthy for no reason
  Skoda Fabia vRS

Ben, the 16v came out in 91/92 long have fully synthetic oils been out ?....did they exist when the 16v was developed ?.....reason i mention this is have you ever seen a 0W or 5W semi synthetic ? doesnt exist afaik......the lowest cold rating you can get in a semi is 10W, which is all they had back when the car was developed

so if they didnt exist then it aint gonna be in the book is it ?

i think they came out in 1994/95

back when the orignal f7p came out in the 19, the recommended oils wer 15/20w50 mineral oils. today they recommend semi-synthetic, or for total protection fully synthetic oils. i used mobil 1 0w40 in my valver at 86k miles. ran happily on it, jsut cost heaps for top ups!! so i stick to regualr 10w40 semi-synth for 9.99 a tub. change it every 2k miles, and il keep the engine happy for miles. im on 127k now, and its still running fine, touch wood


Yeah... I use Mobil 1 0w-40 too... Some people say its too thin so BRUN s research is welcome! Bloody expensive though!

As for mixing oils... I think youre NOT supposed to mix Synthetic with Mineral oils... Read it somewhere...

Personally i think as long as you keep your levels at maximum ALL the time and change it and the filter 3-5K you should have no problems no matter what oil you use...
  Skoda Fabia vRS

Mobil 1 is perfectly fine to mix with any oil, even mineral oils, its on the website and in the tech data i have

I used a fully synthetic Comma 5w/50 a few oil changes ago - never again!

It kept a good pressure on idle (1 - 1.5 bar as opposed to 0.5 bar with 10w/40 semi synthetic), but for some reason the temperature was way too high! With 10w/40 s-s, the oil temp stays at about 100degC - but with this 5w/50 f-s stuff it would stay up at about 120degC all the time.

Needless to say, Im steering clear of that particular oil now! My valver was on about 78k when that happened - just after an engine re-build with new valves and valve seats etc, so I doubt it was due to the age of the bottom end?
  Skoda Fabia vRS

thats really strange, maybe it was because that particular oil has a very wide heat range, 5W-50 is quite a difference, and the oil must contain a large amount of additives to make it have both 5W cold rating properties and 50 hot rating properties, so maybe the oil just wasnt up to scratch

which semi are you using now ?

basically....mixing oils is not a problem with newer oils, and you get teh same benefits of synthetic if you mixed it 1:6 with mineral oil and lower cost.

However, the early synthetics were Polyalkylene Glycol and when mixed with petroleum oils it gelled. But oils are past that point now and you can mix petrochemical with petroleum oils. Mobil 1 is a Polyalphaolefin synthetic and others are a Dibasic Organic Ester type, both are the common synthetics used today.

All oils at operating temp (roughly 100 C) are the same viscosity, so the SAE ratings are only there to indicate the temp RANGE at which they work.

The SAE numbers (weights) correspond to teh oils real viscosity. The W means the oil meets the measurement specifications at 0 F and is suitable for winter use.

one of the best ways to think of it (as somebody else put it) is to think of a 20w-50 (e.g.) as a 20 weight oil which will not thin more than a 50 weight oil at temp.

SO, the W rating is the light base oil to which they add polymers to reach the viscosity rating of the 2nd number weight at temp.

RE the misunderstanding of thick and thin oils, the light base (W rating) dictates the temp range use in cold conditions. SO, the pour point ( 5 F above the temp at which a cool oil shows no movement when inclined) reflects the cold viscosity. so a thin (i.e. 0w) is based on a much lighter base than a 20w.....but at operating them, real viscosity will vary only a little. Since an engine at temp needs to run on teh same viscosity oil, not a thicker one at higher temps....only at startup and warmup do viscosity index matter as much.

one last thing, when choosing an oil to use. use one with the least viscosity range for the temps you will be driving in. SO, in a hot country, a 20W-50 is better tahn a 0W-50 as the range is only 30 rather than the 50. This is important due to amount of polymers the manufacturers must add to keep viscosity from thinning out too much. Polymers are coil like structures which when cold are coild up tight and the oil can flow at its normal viscostiy, when the oil heats, the polymers unwind and keep the oil from thinning out as they provide a resistance. BUT, polymers create deposits and, the least the better.....but its not such a prob with synthetics, as they are created rather than modified crude.

phew....bored yet! LOL
  Skoda Fabia vRS

thanks Ben, i knew i was on the right lines but thanks for the tech explanation, i think ill save that for the future

ill send you an email which goes overly into depth and youll be a real oil anorak....the type you deserve to be......then you can continue to be resident oil expert.......


still think its a fetish..;)

the same SAE index as std but in synthetic.......

if not, 15W50 mobil 1 is good performance oil.......
  Skoda Fabia vRS

well, previously i would have said a 10W-50 or 15W-50, but based on what ive been reading im not gonna say those, although they would run perfectly fine on any 16v car

my advice now would be to go for a fully synthetic with as small a heat range as possible, probably a 5W-40, which will still flow very well at cold temps, and will still protect when your givin it some

now im a big fan of Silkolene oils and they do a 5W-40 version of there Pro S, which ive used before in 10W-50, and the Pro R in 15W-50, so i would definitely recommend that

otherwise Mobil 1 would be good, and Elf oils seem to also be good, they do a fully synthetic called Excellium in 5W-40, i might get some of that myself for my next change

if you wanna try the Silkolene you can order it online from

dont go for a 5W-50, the range is very good, but it will be packed with viscosity modifiers to give it such a range, which is a bad thing

its your choice really, but Elf, Mobil and Silkolene are all good oils which ive used before

when not in winter u dont need to go down to a low W oil, so go for a 10W-40 or a 15W-50
  Skoda Fabia vRS

not really sure why, but everyone seems to have mixed results with that, myself i didnt really like it and i know of a few others who thought it was crap aswell, but theres also tons of other people who swear by it
  Clio 1.8 16v

i use 0-40 to and my car seemed to run alot smoother to.u shouldnt use it on turbo cars though due to the turbo s oil rings or sum thin like that!!if u use magnitec when u do an oil change aint all that oil that is held up at the top by the magnitec stay there, there 4 leavin the old oil in?
  Mini Cooper S JCW

i think i need to top my oil up as the needle is nearly on min, but i kept leaving it becoz my drive is on a slight hill and thoughtt his woz affecting the reading.

anway, i am a complete beginner with oils etc.. etc... iv got a 94 16v and il go down the local halfords or similar and get some oil to top it up 2mos.

if some1 could gimme the exact name or brand etc.. of the oil i need to top it up id be very grateful. oh and how much do i need? a ball park price would be gud as well.

Thanx again, Marc
  Skoda Fabia vRS

Marc, id try Mobil 1 for a top up, its 10.99 for a litre at my Halfords

and it isnt just magnatec that sticks to the engine, most semis and i think all synthetics will do that
  Mini Cooper S JCW

BRUN - just plain old Mobil 1??? iv never brought oil b4!!

has it got a model number or nething?
  Mini Cooper S JCW

i see there is 2 sizes there? do i want the bigger or smaller? i guess one is 2ltr and 1ltr??

hi. what about my valver? 94M, currently at 24K miles....think i used 10w-40 castrol GTX last time but i have heard good things about Mobil1. i always let my car idle for 5-10 minutes every morning and make sure not too go past 3000 rpm until oil temp is past 80.......BRUN..what oil should i use for next change? 0w-40?
  Alfa Mito 155TB

I am running a 172 but I think the secret to a good engine is running it in carefully and also letting it warm up before you put your foot down. There are advantages to changing the oil regular and Mobile 1 gives top perfomance. Personally I sleep well at night having the oil changed at the stated service intervals...but I also make sure the oil is at the max ...for top ups I use Halfords own brand synthetic 5w-40w oil..but last weekend in Costco I saw Chevron 5w-40w Synthetic for £11...for 5 litreswhich would do the job equally well....I am only keeping the car for 3 years and approx 40,000 I dont think there will be a problem...But changing the oil after run-in every 6000 miles is great if your doing alot of town work, whereas I do motorway in day out.

My Cup is going in for some warranty work on the 15th of this month and at the same time Im having the Engine/Gearbox oil changed.

The gearbox oil change is being done under warranty (When I had my Mk2 172 and reported a less than perfect gear change they said the first thing they do is change the oil under warranty), it certainly made an improvement last time. I guess its unlikely Ill have any choice as to what they use.....

For the engine, my local dealer has started offering either oem oil (semi) or Mobil 1 (fully synthetic) at additional cost. Ive already told them I want the Mobil 1, but I wanted to ask you guys which viscosity they should be using. Also, what price would you guys expect to pay off the shelf?


  Skoda Fabia vRS

definitely the 0W-40...............the other version......15W-50 would be a bit thick for a new 172

and i think its £34 for 4L

Shouldnt run a brand new car on fully synthetic oil. run mineral oil for the first 10-20,000kms then go onto fully synthetic

mineral oil due have better running in propeties, but you should only need it for the 1st 1000 miles....max.

and ther wont be a problem using 15w50....its operating vicosity is fine.....but it doesnt stand up to harsh winters so well, but Ren wont supply motorsport oil...itll be the 0w as brun said.

At my next oil change im going to use Elf 5w-40 Fully synth as recommended in the hand book. I got some in france the other day when i saw it in the service station. Ill let u know if using the offical oil makes any difference to Magnatec. lol
  Skoda Fabia vRS

yea Ben is right, normal runnin on the 15W-50 will be fine, but winter starts would be a pain, and id go for the 0W-40 myself