Diesel fuel or bio fuels which is best

[izzeybear1]

When refuelling my beast the other day I had the option of a Bio-diesel fuel. But as it was the same price as normal diesel I did not select that option.Has anyone had problems using bio fuel or using reclaimed vegetable oils. I drive an Isuzu MU with a 3.1 engine so do not want to damage it by using incorrect fuel.

 

[colin-yorkshire]

hi Iain

it seems to depend on the car my handbook specifically instructs the user NOT to use bio fuels as this will cause turbo failure.

however a friend of mine uses nothing else but sunflower oil by the gallon with no ill effects ( it is an old volvo 240 20years old)he does use some sort of additive but exactly what it is he won't say.

all I could say is if there is no saving on cost why risk it??

colin

 

[rob_jax]

Iain,

You could be offered four types of diesel fuel:

1. Petroleum diesel to EN590 - this is the fuel everyone is familiar with - has a Cetane rating of 51 (or better), and lubricity additives to protect the injectors and high pressure pump.

2. Performance diesel - such as Shell V-Power, BP Ultimate - and is a newcomer to the garage forecourts - has a Cetane number of 55 (or better), and a top quality additive package.

Independent tests show smoke reduction of 50% or more, and maybe a 5% fuel saving (and better driveability or perfromance) compared to normal diesel. But aside from the smoke reduction, it's probably not worth using on a pre-Euro 3 diesel engine - and I think that includes the Isuzu 3.1

3. Bio-diesel - made by chemically processing vegetable oil (to remove the glycerol present in veg oil), reducing the viscosity to that of normal diesel, and to make it more volatile and easier to ignite.

Pure bio-diesel (known as B100) has a Cetane number of about 53 - and a similar smoke reduction effect - so you should achieve part of the benefits of using a performance diesel. But only if your car is manufacturer certified to be B100 compatible.

However a 5% blend of bio-diesel and 95% normal diesel, known as B5, is widely available in Europe and the UK later this year.

This B5 fuel is certified for use by all car manufacturers - and has the added advantage that the 5% bio-diesel works even better as a pump lubricant than the normal additive - so those items in the engine should be even better protected than before.

4. SVO - straight vegetable oil - or RVO - recycled veg oil - this is plain cooking oil before it's chemically processed into bio-diesel - and is a very different material.

It's much more viscous (thick) and can't be used in any modern diesel engine, even if diluted by blending with normal diesel. Older technology (low pump pressure) diesel engines may use it by blending, pre-heating, or other attempts to reduce the viscosity.

The next biggest issue with SVO and particularly RVO is the amount of free acid that's in them - typically 1% in SVO and much more in RVO - and this has two effects - the acid will etch metal components (and will fail the copper and silver strip corrosion tests for EN 590 fuel); and secondly they naturally go rancid and form gummy residues - and these have big maintenance issues...

Summary:

I'd have no issues using B5 bio-diesel or normal diesel in the Isuzu, the engines ancillaries might even last longer with B5.

I'd need extra information from the manufacturer before using B100 in the Isuzu.

I wouldn't bother using performance diesel in the Isuzu, you won't recoup the extra cost from extra performance / fuel efficiency - the engine and the ECU is just too old in technology terms

I'd never use SVO or RVO in any modern diesel engine. I might be tempted to use a SVO blended with normal diesel in an old technology diesel engine if the price difference paid for any extra maintenance / servicing in the coming months / years.

Robert

 

[izzeybear1]

Iain,

You could be offered four types of diesel fuel:

1. Petroleum diesel to EN590 - this is the fuel everyone is familiar with - has a Cetane rating of 51 (or better), and lubricity additives to protect the injectors and high pressure pump.

2. Performance diesel - such as Shell V-Power, BP Ultimate - and is a newcomer to the garage forecourts - has a Cetane number of 55 (or better), and a top quality additive package.

Independent tests show smoke reduction of 50% or more, and maybe a 5% fuel saving (and better driveability or perfromance) compared to normal diesel. But aside from the smoke reduction, it's probably not worth using on a pre-Euro 3 diesel engine - and I think that includes the Isuzu 3.1

3. Bio-diesel - made by chemically processing vegetable oil (to remove the glycerol present in veg oil), reducing the viscosity to that of normal diesel, and to make it more volatile and easier to ignite.

Pure bio-diesel (known as B100) has a Cetane number of about 53 - and a similar smoke reduction effect - so you should achieve part of the benefits of using a performance diesel. But only if your car is manufacturer certified to be B100 compatible.

However a 5% blend of bio-diesel and 95% normal diesel, known as B5, is widely available in Europe and the UK later this year.

This B5 fuel is certified for use by all car manufacturers - and has the added advantage that the 5% bio-diesel works even better as a pump lubricant than the normal additive - so those items in the engine should be even better protected than before.

4. SVO - straight vegetable oil - or RVO - recycled veg oil - this is plain cooking oil before it's chemically processed into bio-diesel - and is a very different material.

It's much more viscous (thick) and can't be used in any modern diesel engine, even if diluted by blending with normal diesel. Older technology (low pump pressure) diesel engines may use it by blending, pre-heating, or other attempts to reduce the viscosity.

The next biggest issue with SVO and particularly RVO is the amount of free acid that's in them - typically 1% in SVO and much more in RVO - and this has two effects - the acid will etch metal components (and will fail the copper and silver strip corrosion tests for EN 590 fuel); and secondly they naturally go rancid and form gummy residues - and these have big maintenance issues...

Summary:

I'd have no issues using B5 bio-diesel or normal diesel in the Isuzu, the engines ancillaries might even last longer with B5.

I'd need extra information from the manufacturer before using B100 in the Isuzu.

I wouldn't bother using performance diesel in the Isuzu, you won't recoup the extra cost from extra performance / fuel efficiency - the engine and the ECU is just too old in technology terms

I'd never use SVO or RVO in any modern diesel engine. I might be tempted to use a SVO blended with normal diesel in an old technology diesel engine if the price difference paid for any extra maintenance / servicing in the coming months / years.

Robert

Many thanks for your responses. It does answer one query I had. I used an additive to my fuel supposedly to increase mpg by up to 7% One run to London with additive gave 32mpg the next run without gave me 31mpg. I must keep lifting my right foot a little.