rider Posted August 23, 2011 Share Posted August 23, 2011 There was a thread started in the supra chat section that somehow got side tracked into oil change interval and it did look like everyone has their own ideas on the topic but there was a lot of half truths and a few total myths coming up. I did a search on threads and there hasn't really be anything solely dedicated to this topic which is surprising as people seem happy to swap out £50+ worth of expensive synthetic oil every 3,000 to 4,500 miles as a preventative measure. I used to work in oil product development for an oil major and have a lot of experience in what makes a good oil and what breaks down a good oil. Up to 15 years ago all synthethic 4 stroke engine oils were based upon polyalpaholefins (unless for the Swiss lakes biodegradable market when they were ester based) aka PAO's. These are synthetic products that are chemically very stable and so maintained important physical properties for an extended period of time supported by an additive package, chiefly viscosity stability across a wide temperature range coupled with low volatility; both of which are related. Around 15 years ago synthetic oils moved to highly refined mineral oils for the base, basically a very narrow fraction that has high viscosity integrity (high viscosity index - aka. HVI)and doesn't contain light ends, meaning it retains it's viscosity. This switch to HVI mineral oils lowered the base cost by 65%, this left the oil companies very happy as the lower cost was never reflected in the price charged for synthetic oils. The longevity of oils is very reliant upon the additive performance as it is when these are consumed or degraded that oil breakdown can rapidly occur. In large industrial diesel engines the oil is often never changed, just filtered and additive booster packs added. Additive technology has moved on leaps and bounds in the last 20 years - since the Surpa was designed and that is why OEM's can now spec in up to 20K miles change intervals. So, when Supra TT's oil is changed after say 4500 miles you may as well package it up and sell it on Ebay as near new oil or have the oil companies smiling all the way to the recycling bank. The service interval on post 94 Supras is 9,000 miles and with todays oils 9,000 miles is nothing, no matter how hard the car is thrashed. Save yourself some money guys the oil companies don't need it. Quote Link to comment Share on other sites More sharing options...
bignum Posted August 23, 2011 Share Posted August 23, 2011 Interesting reading, i change mine at approx 3k or as soon as it starts to go a bit dark on the dip stick and smelling abit petrolly( is that even a word?), also dont forget alot of folks on here are running twice and even 3 times the power output of the original intended by toyota engine,so the oil gets some stick, i track my car regularly and have done for 10 years now so it gets a hard life, i see an oil change as cheap maintanence, btw i use silkolene or fuchs pro s 10/50 and use it for topping up my van once its dropped out the supra. Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted August 23, 2011 Share Posted August 23, 2011 Would be interesting to hear Opie Oil's input on this. Quote Link to comment Share on other sites More sharing options...
evinX Posted August 23, 2011 Share Posted August 23, 2011 I change mine everytime the oil gets black and starts to get a little tacky, no compromises, high quality oil to, would never consider a cheap brand, keeping my engine bullet proof. Quote Link to comment Share on other sites More sharing options...
David P Posted August 23, 2011 Share Posted August 23, 2011 My practise with engine oil is to 'listen to it'? I keep a regular watch of the dipstick and with fresh oil it doesn't use a drop for ages, but after time it does start using it and that's when I change it. This happens at around 6k miles with my N/A engine using fully synthetic 5W30. Quote Link to comment Share on other sites More sharing options...
Abz Posted August 23, 2011 Share Posted August 23, 2011 Very interesting post! I think for a lot of people it is piece of mind, I am guilty of it. As Gaz said would be nice to get an opinion of an oil manufacture sales person too. Quote Link to comment Share on other sites More sharing options...
imi Posted August 23, 2011 Share Posted August 23, 2011 Interesting post indeed. There are also a lot of members on here with high powered supras who run semi synthetic oil in their cars for years without any issues. Paul being one of them. imi Quote Link to comment Share on other sites More sharing options...
Samurai 20V Posted August 23, 2011 Share Posted August 23, 2011 I used to change the oil on my 4A-GE 20V every 3000kms. I plan on doing the same with the Supra.. Quote Link to comment Share on other sites More sharing options...
mellonman Posted August 24, 2011 Share Posted August 24, 2011 (edited) the manual says 4,500 mile but i pritty much do it every 5 or before a event, the oil is a key part to stop engine wear £40 oil change is nothing to the normal running cost of the supra so why not. i do use semi synthetic though is it better to use fully synthetic? Edited August 24, 2011 by mellonman (see edit history) Quote Link to comment Share on other sites More sharing options...
Tyson Posted August 24, 2011 Share Posted August 24, 2011 For most people mileage will be irrelevant as they don't clock up that many, I do mine every 3-6 months as it does about 3000 a year max but more like 2000. Quote Link to comment Share on other sites More sharing options...
Scott Posted August 24, 2011 Share Posted August 24, 2011 Ive always been annually or 8k, whichever comes first. Anything else is a waste of money imo. Had this discussion on imoc a few times and I also chimed in on the thread you mentioned. Each to their own though. Quote Link to comment Share on other sites More sharing options...
Scott Posted August 24, 2011 Share Posted August 24, 2011 (edited) the manual says 4,500 mile but i pritty much do it every 5 or before a event, the oil is a key part to stop engine wear £40 oil change is nothing to the normal running cost of the supra so why not. i do use semi synthetic though is it better to use fully synthetic? Where are you getting 4500 from? The manual I read said 6k or 6 months for the first 2 services then 12k or annually after that. Edited August 24, 2011 by Scott (see edit history) Quote Link to comment Share on other sites More sharing options...
mellonman Posted August 24, 2011 Share Posted August 24, 2011 Where are you getting 4500 from? The manual I read said 6k or 6 months for the first 2 services then 12k or annually after that. says it in my service book 4,500 minor and 9,000 major not sure what is ment by the minor and major (not sure it say minor or major service but its something like that). Quote Link to comment Share on other sites More sharing options...
Scott Posted August 24, 2011 Share Posted August 24, 2011 says it in my service book 4,500 minor and 9,000 major not sure what is ment by the minor and major (not sure it say minor or major service but its something like that). Japanese service book? That will be kms then? Quote Link to comment Share on other sites More sharing options...
mellonman Posted August 24, 2011 Share Posted August 24, 2011 Japanese service book? That will be kms then? That my friend is a very good point its got all the japanese stuff in it but its in english, it deffinatly said miles. Quote Link to comment Share on other sites More sharing options...
Scott Posted August 24, 2011 Share Posted August 24, 2011 http://mkiv.com/manual/manualtt/maintenance_schedule/ Just found that which says for normal conditions it should be 5k or 6 months. They must have recommended syrup as the oil of choice in that case lol. http://www.euro-spec2000.co.uk/Toyota/Supra/ That looks more normal. Quote Link to comment Share on other sites More sharing options...
mellonman Posted August 24, 2011 Share Posted August 24, 2011 i think the factory recomeded oil was 10-30w as stated by oil cap so that might be why so often? also we all pritty much use 10-40 now so can get away with longer Quote Link to comment Share on other sites More sharing options...
stevie_b Posted August 24, 2011 Share Posted August 24, 2011 I change mine every 6000 miles or every yerar, whichever is sooner. Always interested to hear opinions on this though. Quote Link to comment Share on other sites More sharing options...
imi Posted August 24, 2011 Share Posted August 24, 2011 i think the factory recomeded oil was 10-30w as stated by oil cap so that might be why so often? also we all pritty much use 10-40 now so can get away with longer and the 10-30 was not Ester based Fully Synthetic Oil Quote Link to comment Share on other sites More sharing options...
LolaBoost94 Posted August 24, 2011 Share Posted August 24, 2011 What would you recommend for a 94 tt with close to 100k miles on it? It's currently got Royal Purple Fully Syn 10-30 in it. I'm going to continue with the Royal Purple but should I use a different weight seeming it's got higher miles? Cheers Quote Link to comment Share on other sites More sharing options...
dive_popo Posted August 24, 2011 Share Posted August 24, 2011 I do mine every 3k miles or 6 months, with fully syntetic Castrol edge sport 10W60, no problem since I have the car (2 years) Only street use of the car Quote Link to comment Share on other sites More sharing options...
supra Posted August 24, 2011 Share Posted August 24, 2011 i service mine every 3-4k miles with high quality oil, silkoline or mobile 1....using ONLY a genuine filter... Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 24, 2011 Share Posted August 24, 2011 Annually or every 10K whichever is sooner. The low mileage oil change Toyota recommend is for extreme use, if you look at the top of the schedule. If you do track days I would change the oil every third full day, assuming you drive it hard. People who do virtually all motorway driving with very few cold starts V mileage accrued could probably leave it another 2000 miles between oil changes. I think people waste a fortune changing oil too often Quote Link to comment Share on other sites More sharing options...
rider Posted August 24, 2011 Author Share Posted August 24, 2011 (edited) From my fading memory the recommended service interval on pre 94's was 6,000 miles and this was raised to 9,000 miles for post 94's. That was a long time ago and I bet my last pound that if they were to spec in today's oils they would be at 12,000 miles. The viscosity recommendations went to thinner 0W 30 oils around the time the Surpa was coming out to cater for California fuel saving, lower your emmissions, laws that were being introduced at that time; where the car manufacturers had to show they were working towards improving fuel efficiency. The thinner oils were a quick fix way of adding a few % points to economy and their introduction was for no other reason. Generally, the thicker the oil the better the protection will be afforded at high temperatures so for thrash it nuts I'd go for a 40+ weight synthetic over a SAE 30 grade. The lower number which relates to cold crank properties is irrelevant in this country except on the occassional -20C nights when a 0W can have you cranking faster than a 10W. The only recommendation I have with synthetic oils, beyond leaving it in for the duration, is don't switch brands as seals swell in contact with oil and this does vary dependant on the base oil used. If you have used a brand and then replace it with something different that induces relatively less swell then you run a slight risk of introducing seal (oil) leakage. Edited August 24, 2011 by rider (see edit history) Quote Link to comment Share on other sites More sharing options...
Hellstrom Posted August 24, 2011 Share Posted August 24, 2011 (edited) Well non of my supras have ever rolled when winter, i change oil once a year. afaik syntitic will always be better then miniral or semi. atleast when it comes to lubricate the bearings etc. this is however dont really make a difference. lets say your oilpump brakes. with syntetic oil your bearing would last the longest. how ever its a matter of fraktion of seconds. Syntetic oils last longer aswell. and blends with petrol better. id say a good oil for the supra would be 10w-40. that should be for most people needs. i use Motul 20w60 (Lemans) but my car always stands in my garage tha has around 20c. and i always make sure to get full oiltemp before i start to push it. i probebly get about 500km to 1000km before i change the oil. since i always change oil once a year. aslo if you drive the car with more coldstarts/allaround year i would recomand using like 5-40 oil. having too thick oil on cold crank can actually dmg since the oil is verry thick the oilpressure will be verry high on a cold day. Edited August 24, 2011 by Hellstrom (see edit history) Quote Link to comment Share on other sites More sharing options...
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