Fuel consumption increased after installing manifold insulator/ spacer

[Anthony .]

Hi all,

My fuel consumption on my VE sv6 used to be about 13.5L per 100km around town, and around 11L per 100km when on the highway.

Since installing the insulator, I am getting 15L per 100km around town. If I reset the fuel consumption meter whilst travelling at highway speeds, I am getting about 9L per 100km (positive improvement).

I drive normally and don’t WOT often at all.

Is this normal? I drive exactly the same way I did prior to the installation (maybe a touch more gentle since they provide a touch more torque down low).

The spacer has been on the car for about a solid week now.

I thought fuel economy improvements were to be had more generally rather than only on the highway.

Is this normal?

Cheers

 

[krusing]

May need to smoke Test it !, [Vac leak ?]

I would give it more than a week to evaluate it,
Being you are so used to looking at it randomly,
Now you are looking it all the time,

The system works on an average over a tank, and how it "was" driven
Also depends on the fuel you have filled it with,
There is a lot variables for the averages

IMHO, give it a month for your averages to level out.

 

[07GTS]

weather is getting cooler too so longer warmup times

 

[Anthony .]

Cheers.
Could it also potentially be an improper seal of the gasket maker? Shouldn’t be since I let it dry overnight

 

[Fu Manchu]

I did away with the sealant and used two metal intake gaskets. I cut the nodule off one.

There is likely a vacuum leak and most likely from a hose rather than the insulator.

@krusing mentioned the smoke test of the intake plenum. Just about 100% finds a vacuum leak.

 

[Stuart Crosby]

What was the fix