MPG (not good...)

[MX-5 Lazza]

My work is 20 miles of country roads but I'd still cycle if I thought I wouldn't be killed on the roads on the way

[Munter]

MX-5 Lazza said:

My work is 20 miles of country roads but I'd still cycle if I thought I wouldn't be killed on the roads on the way

I cant be bothered to cycle to work. It makes a terrible mess of the carpet in the hallway.

[NiceCupOfTea]

philmar said:

NiceCupOfTea said:

If you have changed the engine there was a change in the oil pressure sender in about 94 - earlier ones are proper senders, later ones are a worse than useless digital affair that showed "none" or "some" a light would have been better.

Maybe if you didn't swap the sender you went from one version to the other?

Its a 94 car, the needle used to work nicely, moving about when accelerating and easing off etc (or when the engine was struggling ), now just nothing at all, flicks up to the top when ignition is switched on, then flicks to bottom when engine is on. Nothing inbetween. Less than useless!

Sounds like you might have an engine out of a later car - can you get the sender from your old engine?

I get mid 20s from my 1.8, but I do drive it "as intended" I do get over 30 on a run.

[tuglet]

MX-5 Lazza said:

tuglet said:

philmar said:

Any ideas on why my mx5 would only be doing about 16-18 mpg (driving sensibly!)? I thought it would improve when engine changed...

Mk1 1.8 Eunos Roadster used as my daily driver. I'm averaging about 16mpg from each tank of unleaded, but I only live a couple of miles from work so she's not even getting a chance to warm up. On the rare occassion she gets a long run out, the average mpg improves very quickly. Best I've seen is 26mpg.

I know this is PistonHeads so it's probably sacrilege to say this but... why don't you walk?

Fair question.

a) We have offices in Glasgow, Perth and Edinburgh so I need to be mobile. For days when I know I'm working at a different office I take my company hack.
b) I'm a fat lazy barsteward.
c) I give a colleague a lift to work and she's fatter and lazier than me.
d) I get to work with a smile on my face.

I could walk or cycle but frankly I'd rather have the extra 10 minutes in bed in the morning.

[tuglet]

Fruitcake said:

MX-5 Lazza said:

tuglet said:

philmar said:

Any ideas on why my mx5 would only be doing about 16-18 mpg (driving sensibly!)? I thought it would improve when engine changed...

Mk1 1.8 Eunos Roadster used as my daily driver. I'm averaging about 16mpg from each tank of unleaded, but I only live a couple of miles from work so she's not even getting a chance to warm up. On the rare occassion she gets a long run out, the average mpg improves very quickly. Best I've seen is 26mpg.

I know this is PistonHeads so it's probably sacrilege to say this but... why don't you walk?

Indeed. Last time I looked walking was free and so's cycling, come to that.

I'd love a job where I could cycle to work.

It's too far though and I need a car for while I'm there

And I'd love a job where I got paid good money to sit on my backside all day doing the square root of bugger all while the office honey makes me endless cups of tea but... Oh hang on a minute ;-)

I'm sure if you were that desparate to cycle to work you'd work something out: get a job closer to home; move closer to current work; arrange use of a company vehicle while you're there; get up at silly o'clock in the morning and get on your bike... Come on, where's your commitment!

[Fruitcake]

tuglet said:

Fruitcake said:

MX-5 Lazza said:

tuglet said:

philmar said:

Any ideas on why my mx5 would only be doing about 16-18 mpg (driving sensibly!)? I thought it would improve when engine changed...

Mk1 1.8 Eunos Roadster used as my daily driver. I'm averaging about 16mpg from each tank of unleaded, but I only live a couple of miles from work so she's not even getting a chance to warm up. On the rare occassion she gets a long run out, the average mpg improves very quickly. Best I've seen is 26mpg.

I know this is PistonHeads so it's probably sacrilege to say this but... why don't you walk?

Indeed. Last time I looked walking was free and so's cycling, come to that.

I'd love a job where I could cycle to work.

It's too far though and I need a car for while I'm there

And I'd love a job where I got paid good money to sit on my backside all day doing the square root of bugger all while the office honey makes me endless cups of tea but... Oh hang on a minute ;-)

I'm sure if you were that desparate to cycle to work you'd work something out: get a job closer to home; move closer to current work; arrange use of a company vehicle while you're there; get up at silly o'clock in the morning and get on your bike... Come on, where's your commitment!

We're in a recession.

I'm a surveyor.

[tuglet]

Fruitcake said:

tuglet said:

Fruitcake said:

MX-5 Lazza said:

tuglet said:

philmar said:

Any ideas on why my mx5 would only be doing about 16-18 mpg (driving sensibly!)? I thought it would improve when engine changed...

Mk1 1.8 Eunos Roadster used as my daily driver. I'm averaging about 16mpg from each tank of unleaded, but I only live a couple of miles from work so she's not even getting a chance to warm up. On the rare occassion she gets a long run out, the average mpg improves very quickly. Best I've seen is 26mpg.

I know this is PistonHeads so it's probably sacrilege to say this but... why don't you walk?

Indeed. Last time I looked walking was free and so's cycling, come to that.

I'd love a job where I could cycle to work.

It's too far though and I need a car for while I'm there

And I'd love a job where I got paid good money to sit on my backside all day doing the square root of bugger all while the office honey makes me endless cups of tea but... Oh hang on a minute ;-)

I'm sure if you were that desparate to cycle to work you'd work something out: get a job closer to home; move closer to current work; arrange use of a company vehicle while you're there; get up at silly o'clock in the morning and get on your bike... Come on, where's your commitment!

We're in a recession.

I'm a surveyor.

All the more reason to walk or cycle. It's free you know ;-)

[Fruitcake]

tuglet said:

Fruitcake said:

tuglet said:

Fruitcake said:

MX-5 Lazza said:

tuglet said:

philmar said:

Any ideas on why my mx5 would only be doing about 16-18 mpg (driving sensibly!)? I thought it would improve when engine changed...

Mk1 1.8 Eunos Roadster used as my daily driver. I'm averaging about 16mpg from each tank of unleaded, but I only live a couple of miles from work so she's not even getting a chance to warm up. On the rare occassion she gets a long run out, the average mpg improves very quickly. Best I've seen is 26mpg.

I know this is PistonHeads so it's probably sacrilege to say this but... why don't you walk?

Indeed. Last time I looked walking was free and so's cycling, come to that.

I'd love a job where I could cycle to work.

It's too far though and I need a car for while I'm there

And I'd love a job where I got paid good money to sit on my backside all day doing the square root of bugger all while the office honey makes me endless cups of tea but... Oh hang on a minute ;-)

I'm sure if you were that desparate to cycle to work you'd work something out: get a job closer to home; move closer to current work; arrange use of a company vehicle while you're there; get up at silly o'clock in the morning and get on your bike... Come on, where's your commitment!

We're in a recession.

I'm a surveyor.

All the more reason to walk or cycle. It's free you know ;-)

Touche

[MX-5 Lazza]

Bob Pain who is the Area Rep for the MX-5 OC West London Area used to drive about 3 miles to work every day in his Mk1 1.6 and later in his Mk1 1.8. Both cars sounded like a bag of spanners as the TLAs rattled constantly due to getting clogged up with old oil that never had a chance to get warmed up. They were also both pretty slow, again because they were choked up having been driven almost constantly cold. He's driving a Mk3 2.0 Sport now...
It's bad for engines, especially on these cars which really need to be warmed and thrashed regularly to keep them running well.

[tuglet]

MX-5 Lazza said:

Bob Pain who is the Area Rep for the MX-5 OC West London Area used to drive about 3 miles to work every day in his Mk1 1.6 and later in his Mk1 1.8. Both cars sounded like a bag of spanners as the TLAs rattled constantly due to getting clogged up with old oil that never had a chance to get warmed up. They were also both pretty slow, again because they were choked up having been driven almost constantly cold. He's driving a Mk3 2.0 Sport now...
It's bad for engines, especially on these cars which really need to be warmed and thrashed regularly to keep them running well.

Would changing the oil every 2000 miles help to limit the damage?

[skinny]

not really. the deposits in the engine (combustion chamber and inlet valves) are from always running super rich - you have to dump loads of fuel in because only the fuel that evaporates burns. the rest of the fuel that remains liquid causes black carbon deposits.

the oil is a seperate issue - as fuel burns it creates water vapour. this will always get past the piston rings and into teh oil in the crankcase. with a short journey, the temp of the oil never gets high enough to burn this water off, and you'll get sludge and gunge. more frequent oil changes would help this, but not deposits.

you will often see cars on teh dyno that have not been driven hard chuck a *load* of black smoke out the back on the first few runs - this is the deposits being removed by the engine being run properly.

[tuglet]

skinny said:

not really. the deposits in the engine (combustion chamber and inlet valves) are from always running super rich - you have to dump loads of fuel in because only the fuel that evaporates burns. the rest of the fuel that remains liquid causes black carbon deposits.

the oil is a seperate issue - as fuel burns it creates water vapour. this will always get past the piston rings and into teh oil in the crankcase. with a short journey, the temp of the oil never gets high enough to burn this water off, and you'll get sludge and gunge. more frequent oil changes would help this, but not deposits.

you will often see cars on teh dyno that have not been driven hard chuck a *load* of black smoke out the back on the first few runs - this is the deposits being removed by the engine being run properly.

Would a good dose of Wynns Carb cleaner reach the right bits?

What about a weekly "Italian service" i.e. a B Road thrashing every Sunday morning for an hour or two? Would that help to keep the deposits down?

E.T.A. I've just started another thread regarding fault codes. I'm getting a 10, 13 and 14. Could these be compounding the problem?

Edited by tuglet on Thursday 20th November 18:21

[Fruitcake]

tuglet said:

What about a weekly "Italian service" i.e. a B Road thrashing every Sunday morning for an hour or two? Would that help to keep the deposits down?

I recommend the use of a heavy right foot wherever possible.

Helps my fuel consumption no end

[tuglet]

Fruitcake said:

tuglet said:

What about a weekly "Italian service" i.e. a B Road thrashing every Sunday morning for an hour or two? Would that help to keep the deposits down?

I recommend the use of a heavy right foot wherever possible.

Helps my fuel consumption no end

I've got a special pair of driving shoes with lead soles ;-) I'm seldom below 5k rpm, which probably isn't good considering my engine is always cold :-(

[skinny]

i don't think you need to thrash it for an hour two (unless you want to, it won't do any harm as long as the engine is nice and warm). i try to give mine a few full throttle blasts through 2-3-4 or 3-4-5 each journey

[tuglet]

skinny said:

i don't think you need to thrash it for an hour two (unless you want to, it won't do any harm as long as the engine is nice and warm). i try to give mine a few full throttle blasts through 2-3-4 or 3-4-5 each journey

Any thoughts on the Wynns carb cleaner? Will it do any good or is it snake oil? I also use Redex or STP injector cleaner occassionally on the basis that it can't do any harm and it only costs a couple of quid.

[NiceCupOfTea]

Well it's not carbed, so not sure what you are suggesting. I chuck some Wynn's Hydraulic Lifter treatment in the 710 filler from time to time though.

[pmanson]

Ours is still returning 250 miles to the tank following the service (oil, plugs & 02 sensor).

Although that is probably the journies it is doing:

First thing Amy drops me at the station (2 mile round trip) before going home, then she drives a mile to her friends about an hour later before they do the 16 miles to work (mixture of 30mph, 60mph SC and 70mph DCs.

In the evenings Amy drives home from work then half hour later comes out to pick me up from the station.

I'm sure we used to get better MPG out of it but that was probably before we used to the station run in the mornings/evening.

We're also down to just the one car so it used to go to Tesco's at the weekend as well.

[tuglet]

NiceCupOfTea said:

Well it's not carbed, so not sure what you are suggesting. I chuck some Wynn's Hydraulic Lifter treatment in the 710 filler from time to time though.

I read somewhere, thought it was here but may have been on the OC forum, that Wynns carb cleaner sprayed in to the air intake can help to clear out all sorts of gunk. I seem to recall this was suggested as a cure for rough / low idling as I was having that problem at the time. I never did it as I couldn't work out exactly where to spray the stuff. Changed the plugs and leads, and adjusted the base idle instead and that sorted it.

[pmanson]

tuglet said:

NiceCupOfTea said:

Well it's not carbed, so not sure what you are suggesting. I chuck some Wynn's Hydraulic Lifter treatment in the 710 filler from time to time though.

I read somewhere, thought it was here but may have been on the OC forum, that Wynns carb cleaner sprayed in to the air intake can help to clear out all sorts of gunk. I seem to recall this was suggested as a cure for rough / low idling as I was having that problem at the time. I never did it as I couldn't work out exactly where to spray the stuff. Changed the plugs and leads, and adjusted the base idle instead and that sorted it.

I've done this and it helped our rough idle. I've got a link on my PC at home which shows you how to do it - when I get home i'll dig it out and post the link.