How badly does bull bar etc affect fuel consumption?

[stevo68]

G'day All,

I have noticed that since I had the bull bar/winch put on.....I have had a marked increase in fuel consumption...moreso than what I thought. Interestingly though....normally when the yellow light comes on and I wait till it is at the last indicator......when I do the first fill up......the pump pulls up at around 85 litres. Now it does its first pull up at around 81-82 litres.

So not sure if it is a consumption issue or a fuel guage issue. Also have had new tyres put on...so not sure if that is a problem as well. I thought there may have been an impact of sorts...but not like this.....normally I will get at least 650kms before I fill up.....today I filled up at 600kms. It does also seem to wind out more before changing up the next gear...moreso than before.

Any advice/ thoughts? Thanks in advance,

Regards

Stevo

[zuno555]

I noticed bigger diameter and more aggressive tyres changed fuel consumption more than carrying an extra 80kgs around (bar and winch). Even my 40kg roof rack barely affected economy.

If you switched to bigger tyres it affects the overall gearing of your car too.

[Jason789]

Hello stevo68,

My TD5 was getting 875(city) to 950+ km(country) per tank with a factory fitted rubber bullbar. When I put on an ARB bull bar and winch, my milage went down to 825-850 km per tank(city driving) I fill mine to the absolute brim each time I fill the tank so I can keep track of fuel economy.

Cheers,

Jason

[AussieAub]

I noticed the biggest change in consumption after fitting bigger tyres (235/85r16 muddies, so not much difference rolling to yours).
I had the bullbar on before that, but no winch.
Since fitting the winch I can't say I've noticed any difference at all.
I'd put it down to the tyres. As stated before in an above post, it also noticeably changed my gearing, but learning to use the auto box better soon fixed that.

I'm not posting my V8's consumption here because its too embarassing...!! :angel:

[stevo68]

Thanks for the posts......I should note that when Smokey was stock was getting over 700-800+kms to a tank. The new tyres I mentioned......I had them before....same brand/ diameter, just they had worn out. So when I originally fitted them plus roof rack some 2 yrs ago.....there was a decrease.....but would still get 650-700kms. Since the bull bar and winch has gone on it has dropped somewhat significantly....which I didn't think it would to the extent it has. Maybe its a whole combo effect??

Regards

Stevo

[JDNSW]

I would be surprised if the bullbar per se made a measurable difference. However, failure to increase the tyre pressure to keep the tyre flex the same with increased weight could. And tyre type and size will make a lot more difference than a bullbar.

John

[MickS]

Has to be tyres...my economy blew out after I put the 33's on ....

[Yorkie]

also the tyres will give you false km reading so you have to work out the difference between stock and larger tyres and what they do to the speedo.

[Sharkee]

Dont forget that changing tyre size as stated will affect gearing but also will change the speedo reading. I cant remember which way is which but for example because your odometer says you've done 700km does'nt mean you have actually done 700 km, If its reading wrong you may have done 750 or even 650. A good way I found of checking it is with the odometer and speedo on a GPS and comparing the speedo's speed and kilometre clock over on the car with the GPS one. My Pajero I had with bigger tyres was quite a bit out and showing I was getting more k's per tank than I was actually getting. Something else to consider?

[RecMec]

G'evening all,

Since I put the bar and winch onto the Disco I have had no appreciable
difference in fuel economy. At the same time I put on new springs and OME shocks up front and nowadays pay more attention to tyre pressures. Around town I run the Wranglers at 40/44. Consumption on bitumen and good gravel is fairly consistent at about 9.8 l/100, it's a TD5. Cheers.

[B92 8NW]

Some of the responses are anachronic. The fuel consumption has increased AFTER the installation of a bullbar/winch/snorkel, the replacement tyres are the same size as the old ones (265/75) which were fitted for two years BEFORE any increase in fuel consumption was observed.

I reckon you should have a look at the electrical connections near the airbox, sounds like a plug has been knocked off a sensor if its winding out more in each gear than usual - the snorkel installers might have bumped something whilst doing the job.

[stevo68]

Some of the responses are anachronic. The fuel consumption has increased AFTER the installation of a bullbar/winch/snorkel, the replacement tyres are the same size as the old ones (265/75) which were fitted for two years BEFORE any increase in fuel consumption was observed.

I reckon you should have a look at the electrical connections near the airbox, sounds like a plug has been knocked off a sensor if its winding out more in each gear than usual - the snorkel installers might have bumped something whilst doing the job. What he said...bolded part :D. However........I am going to check today to see what pressure they are running at as that could be a factor as I hadnt considered extra weight at front as there has been a drop in suspension height.

Though I had the snorkel on first....before Xmas and fuel seemed the same.....only after Xmas when the bar and winch went on have I noticed the difference....i.e you kind of know what it should be showing at say half a tank and the kms' already done. It's due for a service soon....so will get things doubled checked as at the moment...I may as well have a V8 :o,

Regards

Stevo

[AussieAub]

I may as well have a V8

No...you really don't!! :(
I fancy a TD5....wanna do a swap?? ;):p

[Tombie]

50kms isnt a major loss Steve

Your pump could be off/recalibrated.

Temp affects fuel too, expands when hot etc.

Air density and temp will come into play as well.

Yes the bar allows more air under the vehicle so changes aerodynamics a little.

When was it last serviced?

[d@rk51d3]

I'm not posting my V8's consumption here because its too embarassing...!! :angel:

Can't be any worse than the 30L/100Km I'm getting from my 2-Door Rangie.............. can it? :(

[stevo68]

50kms isnt a major loss Steve

Your pump could be off/recalibrated.

Temp affects fuel too, expands when hot etc.

Air density and temp will come into play as well.

Yes the bar allows more air under the vehicle so changes aerodynamics a little.

When was it last serviced? 50kms is a rough idea......probably more. Normally at say a quarter of a tank gone I will have done around 200kms.......not it is more like 150-160kms. As for servicing......would have been around 8000kms ago, so approx 3-4mths ago. Could suspension dropping slightly at front cause a false reading with the fuel guage thingamajig? Thanks so far for all advice/ thoughts......and no wouldnt really want the V8 :p, been there done that ( and miss it) with the D3.

Regards

Stevo

[isuzurover]

50kms is a rough idea......probably more. Normally at say a quarter of a tank gone I will have done around 200kms.......not it is more like 150-160kms.

... Could suspension dropping slightly at front cause a false reading with the fuel guage thingamajig?

That's not the most accurate way of measuring. If the height at the front has dropped it could indeed change your indicated fuel level.

You really need to record L/100 over several fills of the same driving (as you recorded before BB/winch fitment) to get a representative value.

[stevo68]

That's not the most accurate way of measuring. If the height at the front has dropped it could indeed change your indicated fuel level.

You really need to record L/100 over several fills of the same driving (as you recorded before BB/winch fitment) to get a representative value. Thanks for that.....Bolded part.....now your sounding like my collective mates ;). Problem is I dont have the accurate data from before....more a gut feel and the data I have presented to date. In other words......2 yrs of filling it up and knowing how many k's I usually get, amount of times I fill up per month, what kms have been covered at 1/4,1/2 and 3/4 of a tank.

Since the bullbar and winch.......a noticeable change. If the consensus is that adding that wouldnt have a large impact.....then I need to look elsewhere. Am yet to get to servo....so will be interested to see what pressures are running in my tyres since I got the new ones fitted a few weeks ago,

regards

Stevo

[dobbo]

New Tyres.


265/75/r16


I bet you the old ones were 235/70/R16 or 245/75R16

From my experience

That would equate to a 5kph difference = in a TD5 D2 to about 50km worth of range

[stevo68]

New Tyres.


265/75/r16


I bet you the old ones were 235/70/R16 or 245/75R16

From my experience

That would equate to a 5kph difference = in a TD5 D2 to about 50km worth of range hey mate...and nope...same size tyre.....have been running 265/75 Bighorns for 2 yrs....these are just new ones.

Regards

Stevo

[John W]

Yes it dropped my economy too when I put an ARB bar on about 10 years ago. Also noticed the fan coming on up hills etc. Prior to fitting the bar I had not heard the viscos fan come on. Suggests to me that air flow is not as good as the original. But lifted suspension, bigger tyres roof racks possibly even a snorkel all affect the aerodynamics in a negative waysd.

[clubagreenie]

I fitted a winch without bar (behind the std bar). Has made no appreciable difference to economy, and thats on a 4.6. Also measured the height before and after and was the same (and car wasn't moved while fitting). Mount was made from 600mm of 13 x 6 section with 6mm side plates. Weight of mount was equal to a full length of steel cable but fortunatly the winch came with synthetic.

[Redback]

I think that the auto has a lot to do with your increased economy, it doesn't seem to be as efficiant as the manual when adding extras, (ie) extra weight, I haven't noticed any change in economy with my manual, and I'm running 235/85/16s, roof racks, winch and bar, chipped, drawers in the back, still getting the same economy that I had when the car was basically stock.

Baz.