Bongo Fury

Michael,
I'm HHEEEEEEEEEEEEEEEEEEEEEEEEEERE!
I agree with moonshine re the compression. Most diesels are about 22:1 up to 24:1.
Petrol engines are usually around 11 or 12 :1 (they used to be about 8:1in the good old days of the BMC Mini)
I also would like to know what Lez means by not liking to go back to Dino(? Dinosaur??) oils.
My understanding of the situation after 21 years with Shell Lubricants is that semi-synthetics and synthetics are fine but mileage is a serious consideration.
You should never put either in a new car before it has done any mileage unless the manufacturer does (Saab uses Mobil 1 from factory fill).
The reason for this is that it will not allow the rings to bed in with the cylinder walls, thus resulting in bore glazing and subsequent high oil consumption. This of course will not affect any Bongos unless fitted with a new or fully recond unit.
Conversely putting semi or fully synthetic oil in after about 25,000 miles is IMO a waste of money as wear will have already taken place. these oils will NOT replace the worn away metal!
For the average Bongo, the best course of action is to stick to the manufacturers recommendations viz-a-viz miles between changes, buy the most modern diesel specific oil(as far as API spec goes. The API spec should change about every 4 years and it is the additive packages that improve, not the base oil. A modern engine would most likely be in big trouble if run on a 1980's spec oil) you can afford of the NON Synthetic variety and don't get too sexed up about viscosity unless you live somwhere VERY cold.
The mileages that most Bongos will have covered them will enable them to run on a higher viscosity (thicker) oil than that recommended when they were new and if there is a propensity to use more oil than it should, the higher viscosity should help the oil consumption.

Thanks chums

The reason I mentioned the Bongo being high compression (even for a diesel, which I know are a lot higher than petrol) is because I read on BF that the Bongo engine was the Ford Ranger diesel but with a higher compression head. Assuming that is true, it might account for the short oil change intervals on a Bongo? But I'm no expert on these things so just guessing.

Mike

I think good oil is cheap maintenance. I go for the best rated diesel specific oil I can get. I have no concerns about extending the service interval to 6000 miles with decent oil. I use a fully synthetic 5W30 Comma that costs about £13 per 5L. I find this a good compromise between the rubbish and the overpriced big-brand stuff. A big give-away to the quality of the oil is the colour. The lighter it is the more refining it has had. Some of the cheaper oils look to be one step away from crude. I am sure the Halfords branded oil is good but cheap it aint.

Semi-synthetic is a meaningless description. Semi-synthetic is mineral oil with a tiny percentage of synthetic additives. Semi-synthetic, synthetic blend and synthetic technology are all marketing blurb guff. If you want synthetic oil then it will say fully synthetic or similar.

Smartmonkey,
How many miles had your Bongo done when you started putting Synthetic in?
The main difference (as far as Shell was concerned when we introduced GEMINI) between staright mineral and semi-synthetic is the synrhetic long chain polymer which maintains the given viscosity for much longer periods than ordinay mineral oils.

I don't disagree with either of you but Smartmonkey has a point here about the definition of Semi-synthetic oil. A manufacturer is obliged to add up to but no more than 30% of synthetic to mineral oil. Better than straight mineral yes but by how much as it's conceivable you could be buying something that only has a trace of synthetic in it.

Personally I use a good quality yet cheapish brand of 15/40W semi-synth in a 25L drum and do an oil change every 3000 miles. It's a trade off between economy, quality and peace of mind bearing in mind the age of the engine. If it was brand new then I would probably stump up the extra for fully synthetic.

Veg,
I concur.
But there aren't many Bongos out there with new engines are there?
If mine was new I would do the same as you, but putting fully synthetic in an engine that has never used it before and has covered 60 or 70 thousand miles is a pure waste of money.
My Saab has only done 4k, is worth £22k and is factory filled with Mobil one, so, much as it brings screams of agony from my wallet, I shall continue to use it.

Mine has done about 90K miles and I would expect it to be only very lightly worn. I like synthetics because they tend to be better oils and they certainly last longer between changes. The big factor with diesel oil is the quality of the suspension additives that keep the combustion byproduct out of harms way. I agree about wear affecting the oil rating but I am confident I will still have plenty of pressure on 5W30 at 200.000 miles. I like thinner oil because it improves economy and starting performance. The longer chains that synthetics allow do provide better protection from metal to metal contact as well as being more stable. If I was using a mineral oil I would be tempted to change every three thousand.

I suspect that the service intervals have more to do with the expected duty cycle in Japan. I think the manufactures assume that home market cars will do lots of short runs and I think they are less phobic about spending money on servicing. Mazda may well have specified 6000 mile intervals if the Bongo ever made it as an official import.

If I didn't have a good source for synthetic oil I might just go for a good mineral rather than pay £30ish. Then again I only do 5000 a year so probably not.

Again I can't disagree with either of you but because of the frequent oil change which I think it really needs for the turbo and by the fact it looks shite pretty quickly, I'm loathe to chuck a lot of money at fully synth 3 times a year. I'm still of the trade-off viewpoint.

smartmonkey wrote

I use a fully synthetic 5W30 Comma that costs about £13 per 5L

Veg_Ian wrote

I use a good quality yet cheapish brand of 15/40W semi-synth in a 25L drum

OK chaps, any chance of advising where said items might be bought? I paid £21 for my last 5l at Halfords

Yours in Hope (and on behalf of the poor folk of the Bongo Tribe)

Mike

Well I use TESCO diesel oil which is the latest API spec and I change it and the filter every 3000 miles which for me is once a year.
There's no way I am wasting my Shell pension on synthetic oil for something that is not a very expensive up market motor. Dog wagon and stationary engine tug is what Bertie is and he does it very well and very happily.

Hi Mike,
I got an account at the local car spares cash and carry. It's the place that supplies the car shops. With a bit of ingenuity you can get the required bits and pieces to start an account no problem. The car shops seem to have 100% mark-up so it's worth the effort if you go through a bit of stuff like me. A few examples:

5W30 fully synthetic 5L £11.40
10W40 semi-synthetic diesel oil £7
Vectra drop-links £4.50
oil filters around £2
Air filters around £3.50

All plus vat. They only stock good quality stuff like Fram.

Hello SM

Thought I'd PM on this one, but the prices you quote are v attractive for a DIY mechanic like me. Is it really possible for a very occasional buyer to get an account like that? If they allowed it to happen, wouldnt it hit the wallet of the car spare shop (my local one is small and locally owned so its not as though I'd go unnoticed b the big machine)? Or don't they care because the get buy stuff cheaper anyway for trade use? And finally, what kind of evidence would I need to produce in order to get an account like that?

Happy to receive your frank views & thanks for the tip

Mike

Well I am just a DIY mechanic as well but I seem to go through a fair bit of consumables. I also get all the stuff for friends and pass it on. My profession has nothing to do with cars (process engineer and chemistry).

You will need a few bits of ID and some sort of trade association. That might just be a letter head or it might be an invoice with a trade name on it. If you can find a friend with a vat number you are sorted - it doesn't have to be a car buisness, anything will do. The buisness might have a few company cars for example. The main thing is to find your local wholesaler and get the info from them because it depends on the company.

Thanks for the tips - I'll try and follow it up.

Mike

An oils and lubrication specialist from BP who Was sharing an office where I work recently on an engineering project was asked a simple question: Is Synthetic worth it for home use in cars etc or what is the best oil for a car.
His answer echoed Colins comments on Oils (read the fact sheet in the members area)
essentially the answer is probably not. A fully synthetic oil is less prone to cracking (breaking down in to an emulsification due to heat/pressure and time) it is perhaps an oil that you could leave in a vehicle for a couple of years if you didn't bother a decent servicing regime although no matter what oil is used the oil system should be flushed out regularly and a filter change to remove any particulates.
The semi synth option is more bearable on cost and the oil is a longer life oil than the original mineral oil. But if doing an oil change doesnt bother you then the best most cost effective solution is to get the Supermarkets own oil and do twice as many oil changes (change the filter every other change)and so long as the correct viscosity and APi rating is adhered to the vehicle will benefit from having superclean oil running through it.

The big advantage of this is that the lubrication and cooling throughout the engine and cylinder head will be at its best and be less likely to particulate build up.
My own experience is that if you dont skimp and ensure the oils and coolants are changed regularly the engine will look after itself.