Improving Fuel Efficiency

RATM

Just bought a car a few weeks ago and I feel the fuel efficiency could be improved. Someone mentioned something to me about some oil/liquid that is used to clean through an engines parts in the hope of improving MPG. Anybody got a notion of what this is and feedback on results?

Black_Knight

RATM wrote: »

Just bought a car a few weeks ago and I feel the fuel efficiency could be improved. Someone mentioned something to me about some oil/liquid that is used to clean through an engines parts in the hope of improving MPG. Anybody got a notion of what this is and feedback on results?

Never used the stuff, but from what ive heard you're spot on. Ill stand corrected if im wrong, but IMO, better driving technique is your best bet at improving your MPG.

si_guru

Ye'd be best to start with a bit of a service and check the tyre pressures are correct.

What is it - petrol or diesel?

You could add Molyslip or Slick 50 to the oil, but expect at best 1-2 mpg more! Really.. you'r best of just putting in fresh, decent oil(decent doesn't have to mean expensive).

Samich

just floor it to get to where you're going quicker, less time on the road!!!

I joke

GTE

I am very sure I have noticed MPG improvements by using Dipetane in my diesel.

Its just bloody hard to find the stuff.

Mar4ix

bbk wrote: »

I am very sure I have noticed MPG improvements by using Dipetane in my diesel.

Its just bloody hard to find the stuff.

http://www.dipetane.ie/BuyDipetane.aspx

RATM

Its a 1.4i petrol (MG ZR, 2004). Have been getting approx 28MPG which seems low?
It will be in for a service as soon as the mechanic returns from Spain. I must check tyre pressures- what would be optimum ? Is about 28-30psi a general rule or is it dependent on the individual tyre?

Mar4ix

at 30 psi perfect. also depend of tire size, if it too wide , it might take more fuel, too narrow, will save more fuel, but wont be safe on road(litle grip), and will worn way quicker. sometimes on drivers door sil or on fuel tank lid inner side sticker with manufacture recommended tire size and pressure in it.

conzy

No matter what the car is its very hard to improve the mpg by more than 10% even with painful driving technique changes

I can drive nice and smooth, go around at 50k in 5th gear so its barely ticking over, coast up to roundabouts etc etc

Or I can drive the car the way it was meant to be driven and get some enjoyment out of it.

I still have to put in 30-40 quid every week..

By the time you buy a high performance air filter, better oil, service it, petrol treatments, oil treatments etc etc that could all go towards a good few full tanks of petrol..

Esel

si_guru wrote: »

Ye'd be best to start with a bit of a service and check the tyre pressures are correct.

What is it - petrol or diesel?

You could add Molyslip or Slick 50 to the oil, but expect at best 1-2 mpg more! Really.. you'r best of just putting in fresh, decent oil(decent doesn't have to mean expensive).

I cannot recommend Slick 50 - unless your engine is basically clapped out already.

C4Kid

RATM wrote: »

Its a 1.4i petrol (MG ZR, 2004). Have been getting approx 28MPG which seems low?
It will be in for a service as soon as the mechanic returns from Spain. I must check tyre pressures- what would be optimum ? Is about 28-30psi a general rule or is it dependent on the individual tyre?

Thats a bit low, but to be honest with an engine that size it doesn't take much to hammer Your mpg when You're looking for any bit of power.

EPM

The last week I have been driving like a saint. Solid 120 on the motorway, no hard accelleration, air con and reading the road well ahead. I got 46 mpg out of the tank. I usually get 42-43 with the same usage. At times it was quite painful tbh resisting the urge to overtake, and for the sake of about 60km extra from a tank it was in no way worth it. I'm sure I could probably swing 50 if I cut it down to 100-110 on the motorway and had a little less city driving.

If I was you OP I'd check my tyre pressures weekly, carry as little additional weight in the car as possible, service it on the button and drive in as high a gear as possible without labouring the engine. Also, when coming up to lights, going downhill don't put it into neutral. Just leave it in gear until just before it starts to chug. The engine uses zero fuel when doing this in gear. It's been the most beneficial fuel saving step I ever made as I had a bad habit of freewheeling it.

TestTransmission

bbk wrote: »

I am very sure I have noticed MPG improvements by using Dipetane in my diesel.

Its just bloody hard to find the stuff.

Where are you?

C4Kid

C4Kid wrote: »

Thats a bit low, but to be honest with an engine that size it doesn't take much to hammer Your mpg when You're looking for any bit of power.

100bhp in a small car like a ZR?

OP, you should see very close to 40mpg on a long run, if you don't the CTS (coolant temp sensor) is the best place to start looking for something wrong. On mixed driving the high 20s is about what the K series returns.

How are you measuring your mpg?

langdang

RoverJames wrote: »

if you don't the CTS (coolant temp sensor) is the best place to start looking for something wrong.

also, maybe a thermostat stuck open (or removed altogether by someone deeply suspicious of rover engines:D)

langdang

langdang wrote: »

also, maybe a thermostat stuck open (or removed altogether by someone deeply suspicious of rover engines:D)

Yep some folks do remove the stat (lunacy), the temp needle would be waving like mad though. The stat on them is a bit of a pain to access too.

Joe 90

RoverJames wrote: »

100bhp in a small car like a ZR?

OP, you should see very close to 40mpg on a long run, if you don't the CTS (coolant temp sensor) is the best place to start looking for something wrong. On mixed driving the high 20s is about what the K series returns.

How are you measuring your mpg?

Depends on what the K is in. When I had the Elise it did a damn sight more when driving more or less legally.
The Exige of course is a different storey.:)

si_guru

Joe 90 wrote: »

Depends on what the K is in. When I had the Elise it did a damn sight more when driving more or less legally.
The Exige of course is a different storey.:)

Agreed... mine was 38-42 however you drove.

Joe 90

Joe 90 wrote: »

Depends on what the K is in. When I had the Elise it did a damn sight more when driving more or less legally.
The Exige of course is a different storey.:)

a ZR would weight in at quite a bit more than an elise though surely.

GTE

Mar4ix wrote: »

http://www.dipetane.ie/BuyDipetane.aspx

all you like.

Im based in Belfast and the local shops that the site say stock Dipetane are not reliably stocking it. I have good reason to say what I say.

TestTransmission wrote: »

Where are you?

South Belfast. I keep looking for the larger drums of the stuff. Spent a free day in May looking around the site and could get nothing. They do have a different name for it up North though.

Joe 90

RoverJames wrote: »

a ZR would weight in at quite a bit more than an elise though surely.

Yes, that's what I meant.

pa990

whats the price for a 5L bottle of dipetane?

any ideas on the cheapest place in cork for it?


edit
i found it in Motorway (opp hardly normals) for €37.80 per 5L

irelandspurs

bbk wrote: »

I am very sure I have noticed MPG improvements by using Dipetane in my diesel.

Its just bloody hard to find the stuff.

motor factors by me have it all the time

savagecabbages

Theres also the craze of putting massive pressure in your tires to improve efficiency. 60psi for example. Bloody dangerous if you ask me!

Was it Michelin who have recently advertised tires that improve fuel efficiency?

GTE

irelandspurs wrote: »

motor factors by me have it all the time

Don't go through your parts.

savagecabbages wrote: »

Theres also the craze of putting massive pressure in your tires to improve efficiency. 60psi for example. Bloody dangerous if you ask me!

Was it Michelin who have recently advertised tires that improve fuel efficiency?

Yes, 80 litres over 28,000 miles.
http://www.michelin.ie/tyres/michelin-energy-saver?fromTyreSelector=true&width=205&ratio=55&radial=16&load=91&speed=v

savagecabbages

Yeah that was it. 80 litres over its 'lifetime'
Fooling no-one there...

Reminds me, bought wipers at a factors yesterday, and there was a stand full of 5L drums of Dipetane right next to the counter so it is selling in Limerick (not that i'd have any use for it)...

Monty.

I're tried additives, but they're just short term snake oil in my opinion.

In a diesel, try to keep rpm under 2000 as much as possible, it makes a big difference. In practice that means no racing take offs at junctions and lights, and driving at about 55mph on longer Journeys. Not as hard as it seems, I just pull over and let the people in a hurry to get stuck behind the next lorry pass out. I always meet them again at the next junction or behind the next lorry. They get no where faster, they're just wasting their fuel.

Over the last few years I've altered my driving style, and now I get 53mpg every time instead of 47mpg every time in the past. That saves me €400 per year, not to be sneezed at. It pays for a extra holiday in the Sun every year. As an extra bonus, I also find that breaks, shocks, bushings, bearings, clutches, etc. etc. all last for much longer miles.

It's not for everyone, but thankfully I've got over the racing stage for day to day commuting.

RATM

RoverJames wrote: »

100bhp in a small car like a ZR?

OP, you should see very close to 40mpg on a long run, if you don't the CTS (coolant temp sensor) is the best place to start looking for something wrong. On mixed driving the high 20s is about what the K series returns.

How are you measuring your mpg?

OP here. Right I should also say that virtually 100% of my driving is city driving with a lot of lights roundabouts, etc. Does 29MPG still sound low for city driving?

I'm calculating it on the basis a full tank of petrol is €60-62, dividing that by €1.50 to deduce its a 40 litre tank. AFAIK there is 4.5 litres to the gallon, so I have a 8.8 gallon tank. On a full tank I am getting approx 260 miles, 260/8.8 comes out to 29mpg.

Will check and correct the tyre pressures but am guessing other stuff such as a good filter will need to go in. Price of fuel looks like it will continue rising for the forseeable future so even a 10-15% improvement would work out at a few hundred euro a year saved.

BrianD3

We have a Renault Megane III 1.5 Dci 86 (5 speed, no DPF) and it gives excellent economy. See below. That's 3.7 l/100 km average over 4600 km. That works out at 76 mpg.

Economy seems to have improved slightly from when it was new. Now admittedly, the person who drives it most of the time is a sedate driver and much of their driving consists of pottering around a mid sized town. Still that means a lot of colds starts, short journeys and stop start driving.

Also the fuel computer could be slightly optimistic but unlikely to be a long way off.

Also, I'd expect economy to disimprove somewhat in winter conditions. By maybe 5 - 10%.

Monty.

BrianD3 wrote: »

Also the fuel computer could be slightly optimistic

They often can be.

Using the brim to brim method is pobably the best way to check the accuracy.

RATM

RATM wrote: »

OP here. Right I should also say that virtually 100% of my driving is city driving with a lot of lights roundabouts, etc. Does 29MPG still sound low for city driving? ...........

Not to me, you're average speed would be less than 20 miles/hour, your time is spent speeding up and slowing down. 29mpg sounds grand to me.

MetzgerMeister

RoverJames wrote: »

100bhp in a small car like a ZR?

105

einheisserschre

einheisserschre wrote: »

105

103 being exact, 105PS

fryup

savagecabbages wrote: »

Theres also the craze of putting massive pressure in your tires to improve efficiency. 60psi for example. Bloody dangerous if you ask me!

what 60psi:eek: people are actually doing that??

Esel

RoverJames wrote: »

Not to me, you're average speed would be less than 20 miles/hour, your time is spent speeding up and slowing down. 29mpg sounds grand to me.

In a regular stop/start scenario, it would probably be more accurate to reckon by time rather than distance - like an aircraft, or an off-road vehicle. That is to say, by the number of hours then engine has been run, rather than the distance travelled.

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