I didn't buy my ZX for fuel economy, however, how many miles do most of you guys get from a tank full of petrol. So far, filled up and used 1/4 of a tank for about 50 miles around town without being a total hooligan. Am about to do a 200 mile trip later this week and wondered if how many times I need to fill up? Could be in need of a serious service tune up!

All depends on how you drive if you car is modified and if it's running well.

 

I get about 16mph around town, but on a longer drive I can get about 22mph traveling round 70-80 mark.

 

A full tank gets me 200 or so miles round town, on a long trip, about 250-280miles

 

Stuart

Thanks, lets see how I get on...any less and the tune uo / service will be next on the list of "things to do"

 

I switched to synthetic oil and watched my fuel consumption go from 16-20 mpg to 24. It can also help to use platinum plugs and a good synthetic in the tranny and differential (for MT). If your fuel economy is really poor, you may need to get your injectors professionally cleaned.

 

You can also nurse the vehicle (keep it in the highest gear possible), turn off the engine at stoplights if the wait will be greater than half a minute (that seems to be the break even point, since it requires quite a bit a fuel to restart the engine, even when warm), and turn the idle down to about 7-800.

 

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--Maxx

I switched to synthetic oil and watched my fuel consumption go from 16-20 mpg to 24. It can also help to use platinum plugs and a good synthetic in the tranny and differential (for MT). If your fuel economy is really poor, you may need to get your injectors professionally cleaned.

 

You can also nurse the vehicle (keep it in the highest gear possible), turn off the engine at stoplights if the wait will be greater than half a minute (that seems to be the break even point, since it requires quite a bit a fuel to restart the engine, even when warm), and turn the idle down to about 7-800.

 

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--Maxx

Platinum plugs are standard on a Z.

 

And an increase from 16-20 to 24 ? What were you using before you switched to synthetic ? Treacle ?!?!?

I noticed a huge improvement in fuel economy with the warmer weather. Methinks the temp sensor keeps the engine on rich a long time in winter whereas in summer it reaches running temp in a couple of miles. Maybe ageing temp sensors read the wrong resistance?

Willie

Actually I have gone a whole week with out needing petrol. I only put £15 in last time and I got over 90miles from it, which it the best I have ever got, and its all short town trips.

 

Stuart

nursing it with synthetic, high flow air filters, even turning the engine off while waiting at long lights

 

with the idle at 2000, though, I just registered a staggering 14 mpg, the worst I've ever seen on my Z

 

maybe I've just been racing it too much

 

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--Maxx

 

LOL! Long trips are fine if you don't allow yourself to get teased by BM's, Scoobys etc.

 

Best I have had so far is 330 miles with cruise control sat at 70mph, reckon' I could get over 350 if it was all motorway and no snarl ups.

 

Cheers!

 

RobH

absolute worst I've had is about 14mpg around town (including lunatic driving) and the best I've had is 30mpg up to London and back which is quite good.

Originally posted by WillieO:

I noticed a huge improvement in fuel economy with the warmer weather. Methinks the temp sensor keeps the engine on rich a long time in winter whereas in summer it reaches running temp in a couple of miles. Maybe ageing temp sensors read the wrong resistance?

Willie

 

Reason for this is simple. Warmer air contains less oxygen per cubic foot. Therefore, per cylinder stroke, you need less fuel to mix with less oxygen, so you get better fuel economy - every time the engine fires there has been less fuel injected. The downside to this is that you lose performance... Nice cold air is best for performance

 

CheerZ,

 

Andy

ok duffman - gonna haggle with you on this one

 

colder air (denser) contains more oxygen molecules per cubic foot of air - agree

 

yup, thats why performance is better with cold air, same as using efficient intercoolers, lower air temp going into cyl.

 

why does it increase performance?? - cos the volumetric efficiency of the engine is increasing. anything that increases the volumetric efficency should also LOWER your fuel consumption (unless you boot it more cos of the increased performance! ) as the fuel injected is burning more efficiently.

 

feel free to argue!!

 

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I feel the need, the need for speed!

 

ive always been led to believe by various magazines and tuners that cars perform better in the cold due to (as has been mentioned) the air is more dense, hence more oxygen hence bigger bang.

butttttt..... dont these things overfuel until they reach a certain temperature??? therefore in the summer the car will reach this certain temperature alot quicker than in winter, therfore using less fuel and giving the impression of improved economy???

INCOMMING!!!!

??????

warm up quicker??whats the thermostat for??

maybe true but not talking a vast difference surely,

maybe lower ambient temp would have a bigger effect if you are only doing small journeys,

quicker to cool down after a run so the next time you start it's on choke(what do you call it on an injection car??)

i'll get my coat then!!

--bye--

--neil--

or how about!

the air is less dense in summer making it easier to move the car less drag..etc,

but as temprature rises the road becomes more addhesive taking away the gain you just had!!!

or the heat shimmy off the road when it's hot actually lifts the car so that you float around which uses less petrol!!!

 

I get about 17/18 mpg out of mine its standard still limited and i dont drive it like a girl, nor a racing driver, i dont think i can really complain i knew it wasnt going to be economical and unsuprisingly its not!

 

B19RKS

Damp air increases engine power - not sure exactly why, but think it's similar to the effect of water on a chip pan fire ?? [complete guess].

 

Cooler air is denser, so more potential power. It may mean use of more or less fuel, as it depends how the car is driven/how it controls fuel injection etc. ?? You could get more power from each explosion, so use lower revs, or use similar revs with smaller explosons and save fuel.

Damp air increases engine power - not sure exactly why, but think it's similar to the effect of water on a chip pan fire ?? [complete guess].

Cooler air is denser, so more potential power. It may mean use of more or less fuel, as it depends how the car is driven/how it controls fuel injection etc. ?? You could get more power from each explosion, so use lower revs, or use similar revs with smaller explosons and save fuel.

 

nice answer!!! " it may use more or less fuel" !!! really!!!

 

and the fuel/air mixture doesnt explode (unless you got mega detonation!) it burns & rapidly expands

 

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I feel the need, the need for speed!

 

I said it may use more or less fuel because I don't know - I was explaining why both PaulC and andyduff have logic to their arguments despite them seemingly contradictory - which is right depends on how the engine works and how the car is driven.

 

Fuel and air under pressure explodes when ignited. EXPLODE (Oxford dictionary) - expand suddenly with a loud noise owing to a release of internal energy.

If you REALLY want to get technical, the air fuel mixture combusts. Explosions tend to be quicker, more violent, much louder, and therefore undesireable in an engine.

 

Since cold air is denser, I am wondering why no one has used an air conditioning unit to actually cool down the air going into the intake manifold... like an intercooler, but with uncompressed air.

 

Just as interesting, I've never heard of anyone building a supercharger driven by an electric motor. This would seem the logical thing to do, since an engine isn't called upon for maximum power output except of a few brief seconds to get you through the quarter mile. You can also do away with turbo lag if the battery can spin up the supercharge before the engine needs to perform.

 

Small amounts of boost can also help emissions by improving scavenging of air in the cylinder.

 

BTW, in cool climates, the engine does not overheat as much, so the fan has to be run less. That's one more for the cold air camp.

 

 

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--Maxx

Remove your exhaust and you'll hear many loud EXPLOSIONS.

 

Fuel is COMBUSTED as a result of many EXPLOSIONS in the engine, caused by mixing it with air and pressurising it before igniting the mixture.

controled explosions?????

anyway i notice a big increase in petrol consumption in summer than winter,,,,,

because instead of pussy footing around you can leather it everywhere!!!

If you want to hear an air fuel mixture explosion, listen to a ramjet

 

Jet engines, automobile engines, and most other engines use combustion... not quite the same thing. The real difference is timing. Instead of banging against the piston, combustion produces pressure on the piston head all the way through the stroke. Combustion can produce a popping sound, but not so much of that irritating concussion you feel.

 

I'm not sure how this affects fuel consumption, but, there you have it.

 

 

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--Maxx

Look in the dictionary.

sorry Nelson but the air/fuel mixture does not explode. it is a controlled burn. explosion implies a suddon & violent reaction.

 

the fuel burns at a controlled & steady rate, or as Maxx says combusts.

 

thats why we have combustion chambers & not explosion chambers!!

 

when at college we were always slapped down for saying the fuel explodes.

 

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I feel the need, the need for speed!