Fuel consumption

davekmoore · Postby **davekmoore** » Sun May 24, 2009 10:50 pm

My NA6 is using 10.0l/100km. My (heavier) 2.0 8v Golf Cab used to do 8.5. I don't think I'm driving the MX5 any differently except I don't waste as much fuel by braking for corners any more.

The MX5 had a roadworthy only a couple of weeks ago so I would expect the emissions not to be too far out. But it does seem to run a bit rich when cold. At least it seems to burble and to tick over a bit lumpier.

I'm not aware of any engine mods (but if this is a standard one, then it's the quickest and best sounding 1.6 four pot I've ever dríven).

Any observations please?

Jeo · Postby **Jeo** » Sun May 24, 2009 11:38 pm

Shouldn't be that high.

My NA6 with an NA8 engine and an assortment of mods does less than that.

Matty · Postby **Matty** » Mon May 25, 2009 12:35 am

If that's short-trip urban driving, that sounds pretty normal.

StanTheMan · Postby **StanTheMan** » Mon May 25, 2009 7:07 am

short trip's I've done up12l/100 but is mainly about 10L

on the Bathurst run last week about 8.0l/100km.

GP · Postby GP » Mon May 25, 2009 1:55 pm

Same as mine, Not too good I think

Mr Morlock · Postby **Mr Morlock** » Mon May 25, 2009 4:53 pm

Observations- - if you are crawling on the Frankston Freeway daily or the Monash 10 /100 might be the result. Also how are you checking it and over what time frame and conditions. Best way is full tank - use vehicle- refill record fuel used and repeat process. Open road driving should return 8/100 or less.

davekmoore · Postby **davekmoore** » Mon May 25, 2009 6:02 pm

Mr Morlock wrote:Observations- - if you are crawling on the Frankston Freeway daily or the Monash 10 /100 might be the result. Also how are you checking it and over what time frame and conditions. Best way is full tank - use vehicle- refill record fuel used and repeat process. Open road driving should return 8/100 or less.

Spend very little time crawling in traffic. I'd rather divert and drive further than sit still.

2 x full tanks since I bought the car and I use the method above to check the consumption.

JBT · Postby **JBT** » Mon May 25, 2009 6:09 pm

Sounds like excessive fuel consumption for the conditions IMHO.

TieNN89 · Postby **TieNN89** » Mon May 25, 2009 9:37 pm

The Highest I got was 12.03L per 100k that was after a mmm mountain run and track day out at lakeside
That was with a bunch of hwy driving

I avg around 8.5 - 9L per 100k with not much traffic a few sets of lights here and there

But yeah 10L per 100k sounds a tad high if your driving it normally ...

ebola · Postby **ebola** » Mon May 25, 2009 10:13 pm

I get between 480 and 550 kms per tank in my NA6. On a drive to Brisbane I got from Sydney to Beenleigh before filling up. 800kms or so.

http://maps.google.com.au/maps?q=berowr ... 0beenleigh

It was an economy run... Call me James May... :wink:

davekmoore · Postby **davekmoore** » Thu May 28, 2009 6:28 pm

Hmmm. Bit of a petrolly smell inside the cabin and the boot this morning. No smell in the garage though, and no sign of anything on the floor. Tank 2/3rds full and it's been cold here recently so not likely to be expansion/vapourisation.

Where should I be looking for potential small leaks?

Don't know about the O2 sensor. Car runs really well apart from being a bit on the lumpy/(rich?) side when cold. Do I replace the O2 sensor with a new standard one or look at alternatives?

Postby **mx52nv** » Thu May 28, 2009 7:40 pm

Checking for fuel leaks in a NA/NB:

In your boot, remove the left (passenger side) metal panel which will expose the fuel hose from your fuel lid to your fuel tank. Check all clamps and hoses for leaks and tell-tale marks from fuel dripping. Also it might pay to check that your fuel filter (right rear wheel well between the door and wheel arch) has all the connectors sealed correctly and also other fuel lines within the engine bay (i.e. fuel reg, fuel rail, etc).

Remove & Replace (R&R) any hose, clamp or part that is faulty. If you are not confident or mechanically minded, then pay a MX5-versed mechanic to do the job (e.g. any of the Forum Sponsors).

Hope this helps. :mrgreen:

Les @ MX5 Shop
P.S. MX52NV gets 450km or more per full tank or 150-200km when I am silly. :lol:

davekmoore · Postby **davekmoore** » Thu May 28, 2009 9:06 pm

mx52nv wrote:Checking for fuel leaks in a NA/NB:

In your boot, remove the left (passenger side) metal panel which will expose the fuel hose from your fuel lid to your fuel tank. Check all clamps and hoses for leaks and tell-tale marks from fuel dripping. Also it might pay to check that your fuel filter (right rear wheel well between the door and wheel arch) has all the connectors sealed correctly and also other fuel lines within the engine bay (i.e. fuel reg, fuel rail, etc).

Remove & Replace (R&R) any hose, clamp or part that is faulty. If you are not confident or mechanically minded, then pay a MX5-versed mechanic to do the job (e.g. any of the Forum Sponsors).

Hope this helps.

Les @ MX5 Shop
P.S. MX52NV gets 450km or more per full tank or 150-200km when I am silly.

Thanks for that. It'll be going to a mechanic. Who - south of Melbourne???

Just love the variation in your fuel consumption. It's as if you turn from James May into Jenson Button.

davekmoore · Postby **davekmoore** » Wed Jun 03, 2009 12:45 am

davekmoore wrote:
mx52nv wrote:Checking for fuel leaks in a NA/NB:

In your boot, remove the left (passenger side) metal panel which will expose the fuel hose from your fuel lid to your fuel tank. Check all clamps and hoses for leaks and tell-tale marks from fuel dripping. Also it might pay to check that your fuel filter (right rear wheel well between the door and wheel arch) has all the connectors sealed correctly and also other fuel lines within the engine bay (i.e. fuel reg, fuel rail, etc).

I found a socket set, removed the panel and inspected these hoses and clamps. No leaks, no drip marks. Low on fuel now, which might make a difference? Will check again when topped up.