08' AWD, new engine, poor fuel eco, update

[salle071]

Hello, can I bug you for a comparison? I just came back from a work trip to antoher city, 550kms all highway. Could not get better than 10.5l/100 on a computer calculated mileage. After 350kms fuel gauge was down at just a quarter left (after fill up). Temp. -4C, flat dry road, winter tires on car. Speed at 115km/h steady on cruise. This is about 30% worse than spec. I know it would take a bit more due to winter tires and cold but this much is not right I think. My Subaru Legacy with 160,000kms and old 4 speed auto, permanent AWD burns 8.2L/100km. Exhaust tip looks black around the chrome bezel, indicating rich running. Dealer said they could not find anything in the codes or otherwise, offered injector cleaning for $75. I may look at changing plugs by myself in case there is a bad one. Car has brand new motor replaced under warranty and only 66,000km. Would be nice to get some real world comparisons especially if you live in the colder climate. Thanks!

[bokito]

I just drove my wife's '08 sl awd rogue and i got 10.5L on average for ~80km i drove.(i've reset the trip computer at half way point).
As i was driving I was wondering too since with my FX35 i can get an average of 10L on highway.

[kerrton]

Hi there,

We have an ongoing log of Rogue gas mileage in a sticky thread at the top of the Rogue forum, here is the direct link:

rogue-gas-mileage-real-owner-logs-t274125.html

10.5L/100Km highway is very poor, I get consistently around 8.0 and have gotten as good as 7.5 on summer road trips.

[philipa_240sx]

There a many factors that can effect fuel economy. I live in Ontario, Canada and I typically see around 9l/100km in winter driving. I do use snow tires.

A few things I would point out:

1) Winter gas formulations aren't as efficient. I have noticed a 1 l/100km average decrease in fuel economy. Some of this is due to idling and longer warm up times as well.

2) New engines take a few thousand km to break in. The ECU will also be adjusting it's parameters to the new engine. Don't expect peak fuel economy until at least 5000km have passed.

I would give it a few thousand km to settle out and see. But due to the other factors, you may well not see your fuel economy improve much until the warm spring weather arrives.

BTW, my tailpipe has black carbon deposits around it as well. It's not running rich, it's just the way it is.

[takeshi]

I just drove my wife's '08 sl awd rogue and i got 10.5L on average for ~80km i drove.(i've reset the trip computer at half way point).
As i was driving I was wondering too since with my FX35 i can get an average of 10L on highway.

Always measure distance/volume on a full tank. Note how far you've driven on a tank at fill up. Your fuel receipt will indicate the amount of fuel that you had to replace. Use these numbers to calculate and don't rely on the computer.

Partial tank measurements can end up all over the place and distance/tank isn't quite as useful for comparison.