R36 (wagon) fuel consumption

[Felix]

Hi guys,

Big fan of this forum. Recently bought my first car, an R36 wagon, which now has about 6,000km on the clock. I can't help but think that there is something wrong with my engine though. I live in Collingwood so majority of my driving is proper start/stop, but I still use twice as much fuel as a normal car. I am currently averaging 20l/100km, sometimes more. 70% of the driving is done by my wife, so the car really isnt getting pushed hard!

Anyone have any idea what the cause could be or whether its normal?

Thanks

[szikou]

How many kms do you get out of a full tank.

I have the same wagon and I get about 500 - 550km with about 50km left.

[Felix]

I get about 350 out of it with usually about 30 to go. Sometimes 400 if I have done a lot of highway driving. The current tank will last me 300 if I am lucky.

I went to VW early on and raised the consumption with them and they said that its normal and it will decrease as the engine is run in. I can't see how its still this high though

[Steve]

I fill up at around 380km to 400km, with another 20km to 30km in the tank.

I do give it the beans regularly, and most of my driving is around town...

[Lance B]

I get about 350 out of it with usually about 30 to go. Sometimes 400 if I have done a lot of highway driving. The current tank will last me 300 if I am lucky.

I went to VW early on and raised the consumption with them and they said that its normal and it will decrease as the engine is run in. I can't see how its still this high though

Are you sure it's 20lt/100km? Rather than do the "how many kms/tank", actually do an accurate "how many kms for how much you needed to fill the tank". So, you may do 350kms, but fill it with 46lts, which will be about 13lts/100km.

As for the statement that it will get better as it runs in, I would have thought 6,000kms would have been plenty for it to have run in enough to have the consumption at reasonable levels like about 12lt-13lt/100kms at worst, which is what I get and my car has consistently achieved this for the last 7,500kms of the 8,500kms that are on the odo.

I would like to know about your driving style. Ho0w far do you travel with each trip? If you only go a few kms then, yes, your fuel consumption will be very high as it is basically always running on choke all the way. You really need to be travalling about 15-20min just to get the oil up to temperature and therefore have reasonable fuel economy.

It might be an idea to go for a long run up a freeway for a few 100kms and see what the economy is like. Maybe do the run and then refill it after the run and see what the economy is like. You should get about 9lt or less/100kms depending on how fast you are driving. It will also do the engine a world of good to "get the cobwebs out".

[kleung]

I am currently averaging 20l/100km, sometimes more.

That seems fairly high. I've done almost 7500km in mine, and my average over the life of the car so far is 12.36l/100km. That's with mostly suburban driving, occasional freeway stint. Occasionally in heavy traffic, and always with a fair bit of equipment in the back. The car has been running on Shell VPower from new.

The last two or three tanks have involved a fair bit of freeway driving, and the trip computer has shown an average of ~11-11.5l/100km (reset each time I fill up).

Once or twice I've done a bit of heavy traffic driving, and the average has gone up to 14-15l/100km, but has always settled back down once the traffic moves on.

All of my figures are based on the 'average 2' display (as opposed to the 'average 1' display that resets itself after the car has not been driven for a few hours).

70% of the driving is done by my wife, so the car really isnt getting pushed hard!

Maybe the wife has the R-bug and has been giving it the berries, without your knowledge?

I never thought my first car would be a family car!

Your first car is an R36? You lucky bastard.

[Felix]

Are you sure it's 20lt/100km? Rather than do the "how many kms/tank", actually do an accurate "how many kms for how much you needed to fill the tank". So, you may do 350kms, but fill it with 46lts, which will be about 13lts/100km.

As for the statement that it will get better as it runs in, I would have thought 6,000kms would have been plenty for it to have run in enough to have the consumption at reasonable levels like about 12lt-13lt/100kms at worst, which is what I get and my car has consistently achieved this for the last 7,500kms of the 8,500kms that are on the odo.

I would like to know about your driving style. Ho0w far do you travel with each trip? If you only go a few kms then, yes, your fuel consumption will be very high as it is basically always running on choke all the way. You really need to be travalling about 15-20min just to get the oil up to temperature and therefore have reasonable fuel economy.

It might be an idea to go for a long run up a freeway for a few 100kms and see what the economy is like. Maybe do the run and then refill it after the run and see what the economy is like. You should get about 9lt or less/100kms depending on how fast you are driving. It will also do the engine a world of good to "get the cobwebs out".

Thanks for your response. I have filled it up with 65l and then refilled 65l a week later after having done 300-350kms. Plus the trip computer is consistently above 20.

As I said my driving is city driving (95% of the time). Imagine driving from Newtown to the CBD in rush hour. 10 mins of stop start. My wife is a bit better and occasionally drives it for 30 mins at a time in city traffic. Doesn't get a lot of highway this car at the moment. In terms of driving style, I do tend to find that I am the fastest off the line at the lights everytime, but can't say I actually put my foot down. This car is hard to drive slowly...

If you think the difference can be explained by low oil temperature than that might be my problem! I always knew that would make some difference but 6-7l/100km seemed high.

How often do you recommend doing a highway stint to "get the cobwebs out"?

[Felix]

That seems fairly high. I've done almost 7500km in mine, and my average over the life of the car so far is 12.36l/100km. That's with mostly suburban driving, occasional freeway stint. Occasionally in heavy traffic, and always with a fair bit of equipment in the back. The car has been running on Shell VPower from new.

The last two or three tanks have involved a fair bit of freeway driving, and the trip computer has shown an average of ~11-11.5l/100km (reset each time I fill up).

Once or twice I've done a bit of heavy traffic driving, and the average has gone up to 14-15l/100km, but has always settled back down once the traffic moves on.

All of my figures are based on the 'average 2' display (as opposed to the 'average 1' display that resets itself after the car has not been driven for a few hours).



Maybe the wife has the R-bug and has been giving it the berries, without your knowledge?



Your first car is an R36? You lucky bastard.

I have been using Shell. Reading some of the other posts BP is apparently the way to go, so I think I will be switching. Do you drive for longer periods? 70% of my trips are 5-10mins. As per Lance's comment above, I am wondering whether that is where I am getting it wrong?!

Maybe I need to move further away from supermarket and city

Oh and on the first car bit, yes this one is my first. I always said I would wait until i could afford a Porsche. Then I got married and just had my first kid, so there went the Porsche and here is the R36. One day...

[dopey]

Short trips and driving in traffic are always bad for the economy. R36 are a heavy car with a 4WD system so the engine does have to make a fair amount of effort to get the car moving from a stand. This would account for alot of the high fuel economy figures.

I really love the v6 engine but knowing that it will return these huge fuel usage figures given that I do a lot of driving in traffic put me off the idea. All cars are worse in traffic of course but the heavier the vehicle and bigger the engine the lighter your wallet.

[2muchcoffeeman]

Yes- I am close to Collingwood and most of my trips are short as well.

I am averaging 15L/100km around town. This can drop to 9.2L/100 on a freeway cruise.

[kleung]

I have been using Shell. Reading some of the other posts BP is apparently the way to go, so I think I will be switching. Do you drive for longer periods? 70% of my trips are 5-10mins. As per Lance's comment above, I am wondering whether that is where I am getting it wrong?!

The short drives certainly won't help. 5-10 minutes isn't long enough for the engine to get up to operating temp properly. Have you got any decent long driving trips coming up that involve significant highway miles? Maybe try taking a day trip somewhere on the weekend to see how the fuel economy goes? Where you fill up can certainly have an impact on fuel economy, but, barring anything unusual about the fuel, I suspect that how and where you use your car and your driving style will have a much bigger impact on the fuel economy.

Once you've done a few tests for yourself, it should give you a better idea of why the fuel consumption is so high.

Oh and on the first car bit, yes this one is my first. I always said I would wait until i could afford a Porsche. Then I got married and just had my first kid, so there went the Porsche and here is the R36. One day...

Congrats on the newest addition to your family.

Well, let's face it. The R36 is a lot more practical than the stereotypical Porsche.

[Yevvy]

20l/100kms in a proper morning stop-start is about right, especially on the short runs. no idea why you need a heavy awd 3.6 litre car to drive 20mins a day but i guess you wanted a performance vehicle, so the thurst is the price you pay.

anyway congrats on the purchase

[R36FTW]

I get around 15/L in heavy traffic. I've noticed though if you crawl along at around 10-20kmh the consumption is horrendous on the MFD, if you stop/start its better, which seems odd.

I got 9.0L/100km when driving to Adelaide full highway with a pretty new engine (just over 1000 kms) and seem to get 11.5-12.5L/100km around town in free flowing traffic.

[Wolfman_36]

Felix

If you are concerned about consumption, you may want to consider the following:
(1) Record the kms (odometer) and litres added at each fill
(2) Concurrently record the ave speed and ave consumption (#2 averages on the display) when you fill
(3) Reset the averages

With this data you can:
(a) Correlate fuel consumption with average speed - over a number of tankfuls.
(b) Check the calibration of the in-dash display.

I do this and over 33000 kms on my R36 sedan I have:
- Overall Average economy from tank fills = 13.2 lit/100kms
- Overall Average economy from Trip Comp = 12.55 lit/100kms
- Average of average speeds = 38.86 km/hr
- Always fill with premium unleaded (9

Unless there is something wrong with your car, some influences would be:
* Driving Style
* Traffic conditions and average speed.
* Trip length
* Tyre pressure

FYI I live in North Fitzroy and commute to Port Melbourne every day. The engine temperature is up to normal within about 5 minutes, so a fair part of my driving is with the engine at operating temperature.

My correlation of economy vs speed looks like this....



Note my driving is generally 80% "sedate" and 20% "brisk"

[kleung]

(2) Concurrently record the ave speed and ave consumption (#2 averages on the display) when you fill

I never thought to record my average speeds per tank...what a good idea.

FYI I live in North Fitzroy and commute to Port Melbourne every day. The engine temperature is up to normal within about 5 minutes, so a fair part of my driving is with the engine at operating temperature.

What is your oil temp reading after that 5 minutes? I'm not convinced that the engine is at 'normal operating temperature' while the engine oil is still <50C (no reading on the oil temp readout). In my R36, the coolant temp is up to the middle of the dial within about 5 minutes from a cold start too, but the oil temp usually takes at least 10-12km before it gets up over 80C (stabilizes around 90C +/- 5C).