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Fuel consumption problem

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fedbeast
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Fuel consumption problem

Post by fedbeast » Sat Dec 03, 2022 1:09 am

I’m burning through a lot of gas quick, went empty in 2 days is that normal? When I switch my dash cluster to the mileage left from a full tank it displays 392 miles every time i fill the car up with premium gas and always use shell premium gas. So after i leave the gas station i and drive home about 3 miles away, the mileage drops drastically like by time i got home it showed 372 miles meaning I’m literally getting like 5-10mpg has anyone had this same issue? And I’m not flooring the car or high revving it either, max 3-4k rpm per shift.

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Fuel consumption problem

Post by Rockhopper » Sat Dec 03, 2022 9:04 am

So how many actual miles driven are you getting to a tankful?

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Fuel consumption problem

Post by mmm-five » Sat Dec 03, 2022 12:07 pm

Short distance consumption/calculations are very unreliable...as is consumption when cold as the car will naturally use more to get up to temp.
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Fuel consumption problem

Post by Smartbear » Sat Dec 03, 2022 1:18 pm

fedbeast wrote: Sat Dec 03, 2022 1:09 am I’m burning through a lot of gas quick, went empty in 2 days is that normal? When I switch my dash cluster to the mileage left from a full tank it displays 392 miles every time i fill the car up with premium gas and always use shell premium gas. So after i leave the gas station i and drive home about 3 miles away, the mileage drops drastically like by time i got home it showed 372 miles meaning I’m literally getting like 5-10mpg has anyone had this same issue? And I’m not flooring the car or high revving it either, max 3-4k rpm per shift.
You’re not going to get great economy by revving the car to 4000rpm, have you checked tyre pressures & had the tracking checked recently? These things all make a difference.
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Last edited by Smartbear on Sat Dec 03, 2022 5:13 pm, edited 1 time in total.
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Fuel consumption problem

Post by DevonPaul » Sat Dec 03, 2022 2:42 pm

Bear in mind these are Colonial gallons ;) so will be lower mpg figures.

First thing I'd check is to see if anything is binding - Get the car to 20mph on a quiet road and put it into neutral and see if it freewheels as normal, generally a binding brake cn cause these issues. Also feel th wheels when you stop as one will be ht if a brake is sticking.

MPG display is based on the last x miles driven, and is used along with fuel level to estimate distance left in the tank. So if you are on a long trip at 35mpg then fill up and start driving around town (especially if you reset the mpg when you fill up) then the estimate will drop pretty quickly. Similarly around town we get 20mpg or less, and if I fill up to go on a run I can find the distance to empty actually goes up for the first 40 miles or so.

As for "is emptying the tank in 2 days normal?" For us, a tank can last anything from 2 days to 6 months.
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Fuel consumption problem

Post by mmm-five » Sat Dec 03, 2022 3:46 pm

DevonPaul wrote: Sat Dec 03, 2022 2:42 pm Bear in mind these are Colonial gallons ;) so will be lower mpg figures.

First thing I'd check is to see if anything is binding - Get the car to 20mph on a quiet road and put it into neutral and see if it freewheels as normal, generally a binding brake cn cause these issues. Also feel th wheels when you stop as one will be ht if a brake is sticking.

MPG display is based on the last x miles driven, and is used along with fuel level to estimate distance left in the tank. So if you are on a long trip at 35mpg then fill up and start driving around town (especially if you reset the mpg when you fill up) then the estimate will drop pretty quickly. Similarly around town we get 20mpg or less, and if I fill up to go on a run I can find the distance to empty actually goes up for the first 40 miles or so.

As for "is emptying the tank in 2 days normal?" For us, a tank can last anything from 2 days to 6 months.
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Fuel consumption problem

Post by Mr Tidy » Sat Dec 03, 2022 9:22 pm

The most recent use of the car is what affects the range.

My car would show plenty of range driving on Motorways and main roads over to my sister's, but doing a few miles in London Borough traffic the range would plummet. Then when I set off home it would keep dropping until I got onto clear roads and then it would start to climb!

I think the Average mpg on the OBC gives a clearer picture of actual consumption.
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Fuel consumption problem

Post by enuff_zed » Sat Dec 03, 2022 10:03 pm

Does it matter what the fancy digital stuff tells you? How many actual, physical miles you cover before you run out of fuel is the only thing that matters surely?
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Fuel consumption problem

Post by Pondrew » Sat Dec 03, 2022 10:14 pm

enuff_zed wrote: Sat Dec 03, 2022 10:03 pm Does it matter what the fancy digital stuff tells you? How many actual, physical miles you cover before you run out of fuel is the only thing that matters surely?
Indeed, yes.
OP, it is very easy to work out real mileage. Fill the tank to the brim, reset the trip meter, drive a decent distance then refill it to the brim. Log the amount of fuel, divide that by the miles you've covered. Viola! Real MPG.

"two days to empty" means absolutely nothing. :)
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Fuel consumption problem

Post by Nanu » Sat Dec 03, 2022 11:02 pm

As previously mentioned by DevonPaul, the digital read out in calculated on the amount of fuel left in the tank based on the consumption over the last 10 / 20 miles driven. If you drive 5 miles per day with the engine cold the mpg read out will be drastically low. Drive 50 miles per day all motorway at 50 mph you will get great mpg
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Fuel consumption problem

Post by colb » Sat Dec 03, 2022 11:41 pm

Take a peek at the fuel trims using a diagnostic scanner that can view the fuel trims in live data. Elevated fuel trims will have a dramatic effect on mpg. Usual cause is air leaks in the vaccum system across the engine that lets unmetered air and confuses the exhaust sensor seeing a weak burnt mixture in the exaust from the unmetered air, the mismatch from what the Maf has reported and what its seeing in the exhaust will cause the engine management to demand more fuel to be injected to richen the mixture up. Usually get bad running and idle if its down to air leaks. The fuel trims when viewed should be around the zero mark with little fluctuation upwards depending on the demand on the engine. High fixed readings may well be due to air leaks, checks on all the rubber vaccum hoses and pipes for cracks and holes should be made, replace any defective items you find. If you have a dipstick check for a duff O ring in the tube. Best method of checking the whole system is a smoke test as air leaks can be quite hard to find, smoke will always find them. Another place to check is the rear edge of the intake manifold, there are a couple of rubber blanking caps on some stubs that are not used, these perish, crack and either leak air in or fall off completely. Smoke will usually find these if visual checks fail to.
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Fuel consumption problem

Post by fedbeast » Mon Dec 05, 2022 1:02 am

Wow, very impressed by everyone’s in-depth and detailed explanations and tips. Highly appreciate everyone’s response and definitely agree with everyone and will do a proper mileage check soon. I understand it is a 18 year old car and has been garaged in New York for quite some time so yes the hoses might be cracking or worn out and need to replace all rubber hoses, from vacuum hoses, to radiator hoses, and most likely break lines as well. Again thank you everyone. Btw do any of you order parts from rocksauto? I find their prices to be very cheap same brand as my local auto shops but much cheaper.

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Fuel consumption problem

Post by Mike6 » Mon Dec 05, 2022 7:22 pm

I am surprised no one has mentioned that you should check your air filter as a clogged one will certainly affect fuel consumption. When I got my zed it had a main dealer service history but I am certain judging by the stata of the air filter that it had never been changed.

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Fuel consumption problem

Post by BumpyZ4 » Mon Dec 05, 2022 8:09 pm

fedbeast wrote: Mon Dec 05, 2022 1:02 am Btw do any of you order parts from rocksauto? I find their prices to be very cheap same brand as my local auto shops but much cheaper.
I do occasionally. You have to be careful as they will ship items in your order from different warehouses and charge you shipping from each warehouse. Plus you have to pay for return shipping even if it is a warranty claim. For some parts it's better to pay a little more and get it at the local parts store.
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