Recently my Cav has started to use alot more fuel then normal. I could use to do about 460 miles to a tank but now I am lucky if I get over 300! I put my foot down no more then l used to so I am a bit stumped! It is always serviced on time etc and the fuel filter has been changed plus the dizzy cap and rotor arm etc so it is all going ok. This really sounds dumb but could it be the thicker oil I am now using??!!?? Used to run 10/40 now its on 15/40.
hmm, i get 170-190 miles to a tank in this cold weather. doubt it has much to do with the oil, more like the cold or grimey injectors, try cleaning the throttle with carb cleaner and running some injector cleaner through, usually sees me with 1 or 2 mpg better.
i only got a weener 9 gallon tank Cem
thats a very respectable 20mpg, been like that for years now. its cos i have pushed a smaller capacity engine too much, bound to happen, thats just life. when it was pushing decent power in the spring i was hitting 16mpg engines fluffered now though, totally shagged lmao
in summer i get 240, but thats at the most. 26.5mpg ish, i dont run dry though, i always fill up when it starts flashing me and theres 1 bar left, there could be as much as a gallon left i am told, but i doubt many run dry on a regular basis just to test mpg.
i take it you mean me, since Matt said his were fine...nope, they are all brand new with decent leads and bosch everything else. ecu is sealed up solid with no wires hanging from the loom as it all packaged tight lmao
temp sensor has been changed too b4 you say. that might be summat to change Matt, they are around £20.
the reason is because i have had to work the fuelling hard since it really isnt up to the job and shouldnt technically give more than 135bhp without some pressure and adapting the AFM
theres a whole crapload of air being pushed in, it needs fuel to suit. fuelling itself isnt too bad, ok it would fail the emmissions, but a lot of modded cars do and 4.5% is too damn optimistic to hit lmao (it was still lower than ALs lmao lmao)
I have changed the temp sensor and the thermostat so I 'spose it can't be that? green manalishi could be right (I don't have a/c though) this time of year more things are on. Well..... roll on summer then!
Just to be on the safe side, do a compression test. If I was in your position I would, its got to be a lot cheaper than buying bits and pieces unnessassarily. If the compression is fine then buy away. But if i were losing 160 miles a tank full thats the first thing I would have checked. I use to own a Mazda 626. and it got to the point that £10 would only buy me 60 miles, thats 20 miles a gallon.. I checked the pots, 3 showed 150ish the 4th showed only 40, that was enough I sold the car a week later for a ton + 25. Put both our minds at rest.
You don't need to run the tank dry to calculate mpg - just brim the tank & note the amount of fuel you need to brim it next time, along with the mileage. My valver does 38mpg going to work and back which involves sitting in traffic & crusing at 85mph (on my private road to work that is !)
my valver pulled 45mpg over the weekend at NEC that was heavy motorway use. Heavy being me and animal testing engines. 9 gallon tank, 100 miles per quater tank (motorway 85ish all way home) makes about 44.4444444444444444444444
Bloody hell - I thought mine was good. You wouldn't think that the "same" cars could differ so much.
When I first got mine I followed a mate in his Lotus Carlton to snetterton on a secret private road at a ton most of the way & I got 40 mpg then. That was probably due to slip streaming a Lotus though and the high summer temp !
im really not ahppy with my cav at the mo.i got 31.5 going to nec at weekend.i know it wasnt at 70 all the way but i still think its low.
so im booked in for a rolling road & tune in plymouth on saturday.
i've got 200 miles from 30 litres out of all of my cavs, the 2l 16v works out almost the same as my 1.6l 8v. give or take a bit.
sounds like most people are getting similar.
but Mattj, this week i've only got 150 miles (147 to be precise, i fill up with 30 litres as soon as the warning light comes on). it's been pissing down, and i've had to use big lights in the mist. when it's dry and claer, the windows steam up and i'm using fan and demister. i think the alternator is eating my petrol.
there could be other things wrong with your car, i would check compression etc, but the increase in the amout of fuel your car has started using is similar to me, and i don't think thats a coincedence.
you had 460 miles go to 300 miles
i had 200 miles go to 150...
well your's has increased more than mine, but you were getting more than me to begin with. i've had 460 miles+ (more than 500 once) out of tanks, but not on average.