Fuel Consumption

[Pappy]

Good morning people. I am new to this site and decided to join for the benefit of my girlfriend's daughter. In short - My girlfriend's son gave his sister a Nissan Skyline R31 for her 16th birthday (great guy). She hasn't a clue about these cars and neither do I.

Question - Is the fuel consumption on these cars excessive.

She put $50 of unleaded in the car and only got 175kms out of it. The car has been sitting in the back yard for almost 2 years and has only just been put on the road after getting her P's.

Any help would be greatly appreciated. Cheers...

[mad082]

it could depend on a few things. it could simply be that the o2 sensor is stuffed. this controls the amount of fuel the car uses when just cruising along.

it could be that from sitting around for so long that the injectors are a bit gummed up and not functioning properly.

it could also be that the fuel gauge is a bit dicky as well. for accurate results you really need to fill the tank up to full, reset the trip meter, drive around, when the tank gets low fill up full again and take note of how many litres went in and how many kms were done. you can then use this to calculate the fuel economy into Litres/100kms, and then you can judge how bad the economy is. the info you have given isn't that useful for actually calculating the fuel economy she got.

there is also other variables such as how does she drive? if she gives it a bit of beans every time she takes off she will use more fuel.

there could be other mechanical issues causing poor economy as well. if the catalytic converter is blocked then the car will be losing power so she will have to apply the accelerator more to accelerate. if the thermostat isn't closing properly then the car won't be coming up to temp properly so it will be spending a lot of time on cold start enrichment and using more fuel. there could be a sticking brake. if the oil is old then it could be a bit sludgy and not lubricating the engine that well.

[Pappy]

it could depend on a few things. it could simply be that the o2 sensor is stuffed. this controls the amount of fuel the car uses when just cruising along.

it could be that from sitting around for so long that the injectors are a bit gummed up and not functioning properly.

it could also be that the fuel gauge is a bit dicky as well. for accurate results you really need to fill the tank up to full, reset the trip meter, drive around, when the tank gets low fill up full again and take note of how many litres went in and how many kms were done. you can then use this to calculate the fuel economy into Litres/100kms, and then you can judge how bad the economy is. the info you have given isn't that useful for actually calculating the fuel economy she got.

there is also other variables such as how does she drive? if she gives it a bit of beans every time she takes off she will use more fuel.

there could be other mechanical issues causing poor economy as well. if the catalytic converter is blocked then the car will be losing power so she will have to apply the accelerator more to accelerate. if the thermostat isn't closing properly then the car won't be coming up to temp properly so it will be spending a lot of time on cold start enrichment and using more fuel. there could be a sticking brake. if the oil is old then it could be a bit sludgy and not lubricating the engine that well.

Thanks mad082.

Looks like we need to start the elimination process. I have put injector cleaner in with the first lot fuel and the gauge didn't initially move but now does. Don't believe it's had an oil change for some years so something else to get done. Thought about changing spark plugs and leads as well. We did notice a strong petrol smell when she first put the $50 fuel in but that disappeared when the tank got below 1/2. Another suggestion has been the seals on the injectors and we are having somebody check that out. Car temp climbs pretty quickly and normally sits on 1/2. She does have to give it a bit of stick when 1st starting off as the car takes off slowly.

Thanks for all you help and we'll look into each of those until we solve the problem. Cheers...

[Wacky Dee]

no oil change in several years ?? It doesn't matter if the car hasn't been driven you need to change that oil BEFORE you drive the car not when you get around to it. That should be your #1 priority. It doesn't have to be any fancy oil ie. you can do an oil and filter change for < $50.

Seeing as how it's an old R31 there could be a million reasons as to why its using up so much fuel. For all you know you could have a family of (now dead) possums in the muffler if the car's been sitting in the yard for 2 years. But my bet would be on a stuck brake if it's been under a handbrake for 2+ years.

My recommendation, sell the car as-is and get whatever you can for it and get something a bit nicer/safer that's been maintained. You will save money that way I'm sure of it.

[Pappy]

no oil change in several years ?? It doesn't matter if the car hasn't been driven you need to change that oil BEFORE you drive the car not when you get around to it. That should be your #1 priority. It doesn't have to be any fancy oil ie. you can do an oil and filter change for < $50.

Seeing as how it's an old R31 there could be a million reasons as to why its using up so much fuel. For all you know you could have a family of (now dead) possums in the muffler if the car's been sitting in the yard for 2 years. But my bet would be on a stuck brake if it's been under a handbrake for 2+ years.

My recommendation, sell the car as-is and get whatever you can for it and get something a bit nicer/safer that's been maintained. You will save money that way I'm sure of it.

Thanks 'Wacky Dee'.

Will def do the oil change. Rear muffler has been replaced but the hand brake hasn't worked for a long time. My girlfriend's son, who had it before, said to never put the hand-brake on as it will stay on and not release. If it was up to me I would have sold it already and got her something smaller. The 17yo step-daughter doesn't want to get rid of it cos her brother gave it to her. I will get it to a brake place and get the hand-brake checked out.

Thanks for the help...

[GTR-N1]

something not emntioned or asked so far is this...

Is it an Auto?

The R31 Auto uses noticeably more fuel than a Manual even with reasonable takeoff.

If it's an Auto, I'd get a different car.

If not, then plugs and state of tune.

[Pappy]

something not emntioned or asked so far is this...

Is it an Auto?

The R31 Auto uses noticeably more fuel than a Manual even with reasonable takeoff.

If it's an Auto, I'd get a different car.

If not, then plugs and state of tune.

Thanks Terry_GT-R34.

Yes it is an auto. Worked the fuel out to be 10L/44kms. I think that's pretty bad and as i've stated before, if it was mine i'd get rid of it. Trouble is that she has no money. I'm gonna keep working on her though.

Thanks for everyone's help in this matter...

Thanks for the PM 'jiffo',

I can't send PM back yet as i don't have 10 posts. How much for your wife's VS and i'll put the question to her.

Cheers...

[mad082]

i'd give it a few tanks of fuel (after changing the oil of course), and as i said above, fill it all the way up, reset trip meter, take note of fuel put in and kms at next fill up and check the fuel economy then. that will give you a better (more accurate) indication of what sort of economy it is getting.

[The Bogan]

Service it and dont run it to hard and it should run OK, its a old car and you will never get great economy out of it, also dont keep lots of rubbish in the car, every KG counts.

Hope she enjoys her new ride and make sure she stays safe.

http://www.ianluff.com.au/index.asp?pageid=36 or something simular.

[Pappy]

Thanks for the pics 'jiffo', car looks quite reasonable. I will def work on her about getting another car and will contact you about getting a closer look at it. She has had a look at your pics and thinks it looks nice. Is RWC Road Worthy Certificate and if so, does that mean it needs to go over the pits?..

Cheers...

[Pappy]

Thanks for the extra PM 'jiffo'. We live in Christie Downs SA so a trip to Qld would be a bit of a trek. I appreciate all your help in this matter along with the other users that have responded. Step daughter wants to keep the car for now so we'll work on it piece by piece, or untill she gets sick of it.

Cheers everyone...