Fuel consumption since module & pump repair

mikesmith20001 · Post by **mikesmith20001** » 07 Jun 2010, 11:24

Hello,

A few weeks ago my 2006 Volvo S80 2.5 AWD had its engine fault light come on. Its under Volvo CPD warranty. Took it back to the dealer who said it was showing as having "high fuel pressure or no signal" error. They said the pump was generating more than double the amount of pressure. They changed the fuel module, but light stayed on. They then changed the fuel pump, which solved the problem.

Before this repair i was averaging 16.3 mpg, now I’m getting 15.6 mpg.

I have taken a look at the tires and they were a psi or two underinflated, so i put them to the correct level, but this made no difference. Putting the a/c on or off has little affect. I am doing what i can to avoid the turbo, but i feel i shouldn't have to since i didn't drive like that before.

Any ideas how the two items replaced could be playing a part? I am concerned once winter rolls around and the AWD is used more that fuel consumption will get worse.

This a probably off topic, but i grew up with Volvo cars and they just weren’t this bad before. This car has already had an Alternator, Fuel module, Fuel pump, Handbrake shoes, Bishings, Radiator

Thanks,

Mike

pj8708 · Post by **pj8708** » 07 Jun 2010, 20:10

I have no expertise on this subject, but from other postings on MPG issues one would ask if you are calculating the miles per gallaon from the driver information center, or actualy writing down the gallons put in, miles driven, then calculating.

One would think that a .7 tenths of a gallon differnce in MPG, since it is so small, could be caused by any number of things; i.e. tire temp(might try filling tires with nitrogen),wind resistence, gasoline blend varying from one tanker to another.

mikesmith20001 · Post by **mikesmith20001** » 08 Jun 2010, 05:26

I am using the driver information center, which actually read "15.0 L per 100km", so then then went to an online website to convert that to MPG.

I read somewhere that Volvo's adhust fuel mixture based on the quality of fuel going in. Does anyone know where that calculation is performend?

I guess what i'm trying to say is, is there any calibration needed between the replaced parts and the ECU or am i overthinking it?

Thanks,

mikesmith20001 · Post by **mikesmith20001** » 08 Jun 2010, 05:31

Just had a few thoughts:

1) I was thinking if some other drivers of this model could let me know what MPG they are getting and what fuel type they use?

If its helps, I drive only in town and rarley take it on the highway as i live so close to work and use standard fuel (usually Shell from two diffrent gas stations).

2) Can anyone tell me if they think my MPG is within acceptable limits for this model and my driving conditions?

Thanks in advance.