Improving MPG / Fuel economy.

[KieranEG6]

Noticed I keep seeing people saying that GTiR's are rediculous on fuel.

Have been reading through alot of posts and was surprised to see so little about MPG or how to improve it. There are a few about fixing cars with faults causing higher MPG but couldn't find any on how to improve it in general.

So does anyone know what will help increase overall MPG?? Clearly using the Go pedal less and keeping weight to minimum is the first points of call but surely there must be simple things you can do to keep it resonable. Almost all performance engine's are going small cc turbo's to be better on fuel than N/A so why cant the GTiR be improved?


I have been considering all sorts. Like using thinner oil throughout the transmission like 75w85 instead of 90 to reduce drag, keeping the wheels and tyres as small as is needed, keepin the charcoal canister, getting the car mapped properly, etc...

Surely there must be ways to tune them to be good on fuel and also fast. Was wondering things like will reducing the volume of intercooler and piping make them better being more efficient and responsive or would having a larger volume be better with more lag so to not allways be on boost?

Would be good to hear what people come up with that might help.

(Ps yes I know Its a 2L turbo with constant AWD an is never going to be great on fuel but every little helps.)

 

[PobodY]

From experience, keeping your foot off the loud pedal is the best way to save fuel; nice steady speeds for as long as you can. - If I drive my car to work in stop-start traffic I don't get much more than about 150 miles out of a tank.
If I drive 2 hours to pick-up a seat and the same to come home, I get almost the same distance from half a tank of fuel.

A remap will also improve the fuel efficiency; you can lean the map out for low RPM on the highway, there's not much in the way of engine load so the risk is pretty small. - I'm sure Ed has done this when mapping Nistune for some of his customers.

I don't think you'll improve the transmission loss greatly with a thinner oil; you're still putting power to four wheels through three differentials. - I'm happy to be corrected on this.

The simple answer though is that this is a 20 year-old rally car; fuel efficiency was never a consideration (look at other cars of that age/origin; none of them are fuel efficient).
If you want to save on your fuel bill, but the R in your garage and drive something else. - You need to burn the fuel to make the power; you need to make power to make it go fast. There's no escaping the fundamental laws of physics.

 

[stevepudney]

Noticed I keep seeing people saying that GTiR's are rediculous on fuel.

Have been reading through alot of posts and was surprised to see so little about MPG or how to improve it. There are a few about fixing cars with faults causing higher MPG but couldn't find any on how to improve it in general.

As George says and personally the last thing on my mind if I'm buying or driving a "performance" car is "I wonder how economical it is, hope it does drink to much fuel". Thats like buying a msart car a saying "I hope this goes like a rocket".
If you don't want to spend much on fuel buy an economical car, if you want to go fast, but speed cost money......

 

[skiddusmarkus]

Take a SAFED(safe and fuel efficient driving) course and it will improve your mpg and mechanical sympathy.

 

[Fusion Ed]

Working lambda sensor tyres at a good pressure, and most importantly speeds down to 60odd mph on a run make a BIG difference. Most pulsars I see can obtain 'reasonable' mpg, actually quite a lot better than totally stock ones with cats etc and other emissions control systems still in place.

Main problem for the pulsar is low compression off boost makes them inefficient. Modern cars use direct injection high compression lean burn turbo engines, hence their greater fuel efficiency.

Its not just the pulsar however, even newish evo's etc are just as bad.

 

[KieranEG6]

Thought this might happen.

By all means I don't expect them to be in any way decently fuel efficient at all.

It was more of a question to see if people knew of any ways that help lessen the hole in the pocket or of things that certainly don't help.

Was just thinking along the lines of reducing wasted power and making the engine's run more efficiently with the right tuning.

 

[John]

Thought this might happen.

By all means I don't expect them to be in any way decently fuel efficient at all.

It was more of a question to see if people knew of any ways that help lessen the hole in the pocket or of things that certainly don't help.

Was just thinking along the lines of reducing wasted power and making the engine's run more efficiently with the right tuning.

There is a endless amount of "mods" you could do to make the car more efficient, but really at the end of the day you'll struggle to clear 30mpg at the end of the day.

As others have suggested the biggest thing you can do for improving your mpg is drive more efficiently. Now of course you could go remap your car to run leaner in certain power bands (this costs money so actual financial savings will be negligable), you could improve the cars aero to reduce drag (which again costs money), swap onto low resistance tyres (costs money) etc etc.

You see where this is going, you are going to have to spend money to get a very minimal mpg gain, so is it really worth the effort? The only free things I can think of is stripping your car completely to save weight which will improve your mpg and don't run any electronics (stereo, lights etc etc.....probably not the best idea).

If you keep your car well serviced and drive it sensibly then your mpg will be decent enough......

 

[PobodY]

most importantly speeds down to 60odd mph on a run make a BIG difference. Most pulsars I see can obtain 'reasonable' mpg, actually quite a lot better than totally stock ones with cats etc and other emissions control systems still in place.

Main problem for the pulsar is low compression off boost makes them inefficient. Modern cars use direct injection high compression lean burn turbo engines, hence their greater fuel efficiency.

Its not just the pulsar however, even newish evo's etc are just as bad.

That makes sense to me Ed. - Mine is by no means a high-performance car, but I wouldn't call it stock any more; more boost, but no cat and no PCV; a standard elbow, but a 2.5" exhaust behind it. I guess it's all the mods a "backyard mechanic" can do on their own. :-D

That long drive I mentioned was probably an average speed of ~60mph; I definitely went slower through villages... and may have nudged three figures when overtaking (I blame the scoobie and audi drivers trying to get past me for that).... er but I probably didn't as that would have been exceeding the national speed limit. :shock:

Would a rebuild with high compression pistons improve the off-boost efficiency, or does that just cause bigger problems when on boost?

Following John's logic; take the GTi-R bonnet off and put a Sunny one on (less aero drag), and do the same with the rear spoiler? - I don't know if the spoiler really has any handling benefit; it does feel a little like the car is more planted at speed than when going slowly, but I don't know if that's the spoiler or not (other cars I've driven can fell "loose" at speed which scares you from doing it again... the GTi-R just seems to encourage me).

If you were serious about improving the mpg figure; smaller injectors (physically restrict the fuel delivered); reduce the base fuel pressure? - None of those seem like wise things to me, but with a remap I imagine you could make it work; effectively detune the car in the same way that people fit smaller carburettors to get better efficiency from "big-block" engines.

If there is some good advice/ideas, I'm sure people will pay attention; they may not be any good to someone who tracks their car, but it might be useful for the daily drivers (especially if you could undo it before going to a trackday).

 

[John]

I kind of meant fit a diffuser to the rear and attempt to "flatten" the under side of the car as the rear bumper acts as a parachute hence why I said it would cost money. Of course you coulde remove the GTi-R specific body parts but then why the hell would you as you are essentially removing the cars identity for the sake of saving 10p per tank of fuel!

 

[PobodY]

you are essentially removing the cars identity for the sake of saving 10p per tank of fuel!

I completely agree. - I won't be changing them despite the fact the bonnet scoop is just causing drag since there's no intercooler under it any more.

I'll be honest, I've been watching the F1 and the idea came to me as they were talking about reducing the down force (i.e. drag) to get more top-speed. Thinking about it, the most efficient cars are shaped like a teardrop and have skinny tyres for the minimum rolling resistance... so skinny tyres are another thing to add to the list of mods you could try to save some fuel. - It may have a detrimental effect on handling though.

 

[Makaveli_se7en]

If you are concerned about MPG sell the Pulsar and buy a Polo Blue Motion, job done.

 

[KieranEG6]

Jeez Ill say it again Im really not concerned about making the car have great MPG and of course I know there are things you can do to help that will just reduce the perforance of the car.

I just though it would be a good topic for people to input usefull things they have found that will help. Its not like its a dumb question that gets asked every day.

Whats with all the sarcastic reply's :evil:

 

[wrc]

I understand where you are coming from mate.

We all want the car running sweet with all the mods etc 400bhp plus etc etc - but tbh when you aren't gunning it, which is a lot of the time, you still want sensible mpg. I collect my son every other weekend an it's a 100 mile round trip which I do in the pulsar so like to keep the mpg good.

I just cruise at 60, stay off boost and get the best I can out of it.

 

[t16coupe]

i found a big improvement in mpg when i changed from castrol 10/60 to fuchs 10/50 not sure on what oil you are using

 

[KieranEG6]

i found a big improvement in mpg when i changed from castrol 10/60 to fuchs 10/50 not sure on what oil you are using

Makes sense. Less drag and parasidic drain on the engine.

How much of an improvement?

 

[danr]

Well apart from what's been said by ed, next step is weight saving and aero, ennit? Rip all the seats, doorcards, carpets, spare wheel, toolbox, stereo, speakers, plastics, rooflining etc etc out. Flat panel under car, rear diffuser, smaller wing mirrors, carbon bonnet and boot, plastic windows, fibreglass bumpers and wings!!!! Oh, and stop drinking beer and eating pies ;_)

 

[gtir_pimp]

i found the nistune remap made a huge difference, going from 100 miles a tank to anything up to 160

 

[shroom]

Jeez Ill say it again Im really not concerned about making the car have great MPG and of course I know there are things you can do to help that will just reduce the perforance of the car.

I just though it would be a good topic for people to input usefull things they have found that will help. Its not like its a dumb question that gets asked every day.

Whats with all the sarcastic reply's :evil:

No ita a boring shit topic

Yer i suppose you could say it isnt a dumb question but its a pretty pointless one George pretty much said it all and the others, and im sure it does come up alot, now i just wasted a few minutes of my life reading your boring posts

 

[johnny gtir]

sure i am right in saying plugs make a big difference ie running heat range 7 over 8 more so in the colder months but again running the wrong plug will cause major problems

 

[KieranEG6]

Cost of fuel is one of the biggest reasons to why cars like this have gone down in value so much. Because their cost of running daily is dump.

And how is making your car cheaper to have fun in pointless??

Considering the amount of posts it has gotten in such small time would suggest its actualy an intresting topic. And a Helpfull one at that.