mileage hit when switching to B99

[sleze]

I knew to expect a mileage hit when switching from D2 to B99 but I have noticed a 12% hit. I am going to switch the fuel filter in a day or two after in case there was a lot of sludge in the fuel system but I was wondering:

How much of a fuel economy hit anyone else has encountered with their B5s when switching from dinodiesel to biodiesel?

 

[senez]

That percentage seems pretty close to what values determined through research have shown.

 

[leicaman]

You might want to consider using B5 to B20 blends as that would give you far better mileage plus lubricity of bio.

 

[Sprocket]

I'm surprised at the 12% figure for B99. If you haven't already, please ask this same question in the Alternative Diesel Fuel discussion area. I'm curious to see the replies.

I use B20 year round and have never had any loss of performance or fuel economy. I did use B99 for 2 tanks last summer but I don't remember my fuel economy dropping that much either. Maybe it is the fuel filter.

 

[TomB]

Nope. Not the filter. You are right in line.

It does depends on the source of the BD too. The optimal percentage for the Passat seems to be about B20-30%.

I use B100 and see a difference of 31 MPG in town commute with BD and 34 MPG will all regular dino diesel.

Difference on the highway too.

 

[sleze]

I was out of town for a week and the last two days I noticed that my mileage continued to take a nose dive. Also the engine sound was off and my power was down.

So last night I replaced the fuel filter. Today on the way to work, the car felt much better but, because of the insane amounts of traffic for 60% of the commute, I can't make a fair comparison to D2.

So I guess it is safe to assume that if you switch to B99 after 60k, you will probably need to change fuel filters afterwards.

 

[CsTDI]

I ran D2 until I changed over to B50, with PS additive, around 50k-60k. I lost 1-2mpg. Changing the fuel filter may help. If not, I would consider the possibility of having gotten a bad batch of BD. You may want to see if your supplier's next shipment results in a correction or try another BD source

 

[aNUT]

I loose about 4mpg highway in my golf ~8% on B99