Petrol Issue - Please Help [Archive]

notJDM

07-09-2011, 12:20 AM

I currently own an STOCK 1994 Honda Civic EG (SI). Which I fill up at the Speedway Petrol Station using the normal unleaded petrol, most of the time I fill up near halfway of the tank.

The problem I'm having is that I'm not getting good mileage, it seems that the petrol is drained pretty fast for some reason.

1. Is Speedway unleaded petrol any good? - Could this be the cause of my petrol problem.

2. Whilst driving I always shift at 2000RPM. I always had this thought in my head that the lower the RPM you shift at, the less petrol you will use but I'm still getting poor mileage. - Could this be the cause of my petrol problem? If so, what RPM range to shift at would be the best for my car to save petrol?

3. Another thing I do whilst driving is whenever I'm about to stop or when there's no car. I usually coast/change the gear to neutral just thinking it would save me some petrol by doing that. - Could this be cause of the problem aswell?

So yeah, if anyone knows what is the cause of my petrol draining so fast. Please feel free to comment and tell me or what should I do to fix the problem.

Thanks.

mugen_ctr

07-09-2011, 12:36 AM

notJDM

07-09-2011, 12:54 AM

So what car uses standard 91 unleaded octane fuels then?

Since my car is 1994 Honda Civic EG, will I be able to use fuels like BP Ultimate? - What's some other good fuel company/petrol would you recommend?

I think Speedway is an independent servo, I use the normal unleaded there and most of the time it's around $1.30-$1-40/litre. Though I don't know if the petrol from Speedway is any good. Maybe someone who knows would care to explain?

mugen_ctr

07-09-2011, 01:12 AM

its only recommended, im not saying u should switch to the more expensive 95 ULP, BP98 no need, its over kill, its personal preference, an from my experience, it does make a difference, weather u use normal ULP or PULP is upto you :)

as far as i can gather, camrys and commo are tuned perfectly for 91 octane, but other cars such as Accord Euros and other imports, all need minimum 95 PULP

Me personally, i only stick to BP, 1, being its more readily available, and 2ndly, i find my car responds better with BP over shell

azn_k3nt

07-09-2011, 01:14 AM

91 octane is the lowest recommediations for an old car...give the car 98 and wanna spent some $$$ use 98 ultimate, my advice is serivce the car thoroughly prior giving it better petrol.

About speedway, definitely sounds like a independant. Go for the more well known brands but stick away from caltex and shell. Pricing doesnt really matter since nearly all petrol stations doesnt have a great margain of different +- $0.10. $1.30-$1.40 might as well give it 98 octane

notJDM

07-09-2011, 02:06 AM

quangsuke

07-09-2011, 02:09 AM

service ur car like the above comments.

should really look into your o2 sensor as they is normally the culprit which causes bad fuel economy.

whatever service station you use, you should be still getting reasonable fuel economy.

get your sensors cleaned and make sure u take a look at the fuel regulator also.

redefine

07-09-2011, 09:28 AM

3. Coasting in neutral should technically save u petrol as the engine is just idling, an not actually doin anything, if u were to use engine braking, than yea it would use petrol, but at the cost of coasting to a stop, u use more of ur brake pads, which in terms wears em out quicker, realistically u should be using both engine braking and the brakes em selfs

is the car efi?? only carby's burn fuel at 0% throttle. if your coasting along in gear in an efi car, the fuel should cut...or did this only come in after eg's

trism

07-09-2011, 11:12 AM

When coasting along in neutral, or riding the clutch, the engine will be using fuel to idle. In gear, no throttle under negative vacuum, the engine will use less fuel than idling. That's your first problem.

The second problem is how you're measuring the actual fuel usage. Just guessing isn't accurate. What you need to do is fill it up, until the first click. Reset the kms. Do your driving until it is time to fill up. Fill up to first click again. Record how many litres it took and how many km you drove.

Then divide the l by the km, and then times by 100.

Eg (50÷300)x100= 16.67

A good economy will be between 8 and 10l/100km

The lower the number the better.

Also, the shift point wont make so much of a difference as throttle percentage.

So foot flat to the floor, shifting at 2k will use more than half throttle, shifting at 4k.

mugen_ctr

07-09-2011, 06:42 PM

Thanks, I'm thinking of trying BP Ultimate next time I fill up. Anyone know how much is it per litre? Which days are the cheapest and how much is it on the cheapest day?

Lets also say that my tank is on E, if I fill up around 20 bux will I get about half tank of BP Ultimate?

generally ur looking at 1.50 to lowest of 1.44 per liter, but atm, 1.50 is the norm, regardless of what day of the week unfortunately

on those expensive days, ur looking at 1.55 to 1.60, which is pretty fukkd lol.... but thats the price u pay for fueling up with 98 Pulp

notJDM

08-09-2011, 02:07 AM

generally ur looking at 1.50 to lowest of 1.44 per liter, but atm, 1.50 is the norm, regardless of what day of the week unfortunately

on those expensive days, ur looking at 1.55 to 1.60, which is pretty fukkd lol.... but thats the price u pay for fueling up with 98 Pulp

Keep in mind I come from Sydney. I really want to give BP 98 Ultimate a go, all I know it will be a major difference from Speedway unleaded petrol. I've been looking around at the BP Ultimate prices and it's really shocking ($1.65-$1.70/Litre) though seeing that you said the lowest it can go is $1.50/Litre which I find decent. - may I ask which day is the cheapest to go fill up?

notJDM

08-09-2011, 02:19 AM

The second problem is how you're measuring the actual fuel usage. Just guessing isn't accurate. What you need to do is fill it up, until the first click. Reset the kms. Do your driving until it is time to fill up. Fill up to first click again. Record how many litres it took and how many km you drove.

Yes I know I am not measuring the fuel accurately. Most the time I fill up $20 worth at Speedway which gets me nearly half tank of petrol. But I find that Speedway Petrol seems to drain too fast, I drive around locally and I find that it just drains too fast hence I just filled up.

Where as one day I gave Caltex 95 Petrol a go only filling up $10 worth from an near empty tank and what I noticed It wasn't draining that fast as to Speedway. I could drive around a fair bit and I only filled up $10 worth.

That's why I am curious and asking what you guys think of Speedway petrol. Maybe it's the cause of my fuel running out so quick. If what I'm saying about Speedway is true, then I will need to find a better company to fuel up from. I just need someone to confirm.

Thanks!

trism

08-09-2011, 08:06 AM

Speedway is definitely an independant, and there is no guarantee that the fuel they source is good quality. Buy from one of the majors. Shell, caltex, BP.

You don't have to run 98 octane you can just run 95. It'll be more expensive, but it'll last longer.

Lazarus

08-09-2011, 01:42 PM

I tried the speedway petrol @ the one near cabra with a 07 Camry, and it was a shocker. Cheap as hell, but terrible petrol.
It's abit expensive, but i put BP Ult in my CL9 and definitely worth every cent.

dougie_504

08-09-2011, 04:28 PM

All the advice given is generally good.

- Use better petrol from a company who can afford good R&D. BP, Mobil etc. Shell or Caltex if you have no choice.
- Measure properly. Reset odo, fill to top, calculate L's used and mileage done, figure out your actual consumption.
- Service car.
- Shift at 2,500 or a little less if going downhill.
- Check that your car is reaching optimal operating temperature.

Then get back to us :)

mugen_ctr

08-09-2011, 05:41 PM

There is some truth in saying using bp98 is better, BUT remember our cars, d-series arnt tuned for bp 98, so in essence, BP98 is a waste, as we can never truly make full use of it, the most beneficial cars that need it are performance cars, as 98 lessens the knock levels much better than good ol cheap 91, sure u can tune a car for 91 an make some power, but the chances of knocking is too much to muck around with, an the power output wouldn't be as much compared to tuning to 98 octane fuels.

If i was going to convert my d-series to boost, than yes, im 100percent convince on tuning the car on 98 octane fuels, and only 98.

gumus89

09-09-2011, 10:18 PM

Realistically, honda's are tuned on premium fuels, not standard 91 octane fuels, surprise surprise.... They run much better, and get better mileage

Have u tried servicing the car? oils, coolant, spark plugs etc etc? reset the ecu?, use injector cleaner?

1. Is speedway a independent servo? that might be why as well...
2. Yes and no, optimum shifting should be closer to 2.5-3k as they have short ratios and the power band in d-series is around there
3. Coasting in neutral should technically save u petrol as the engine is just idling, an not actually doin anything, if u were to use engine braking, than yea it would use petrol, but at the cost of coasting to a stop, u use more of ur brake pads, which in terms wears em out quicker, realistically u should be using both engine braking and the brakes em selfs

First, not all Hondas are tuned for premium fuels. Check out the manual, it will tell you. Different engines for different markets will have different tune states. It is very debatable whether higher RON fuels make a difference. Most people see no difference, me included, others do.
All we do know is that for an engine that cant advance its timing in response to higher RON fuels, there is not necessarily any more energy in a PULP and so you probably wont see a difference.
2. Changing at 2k is probably too low. At or below 3k is probably better.
3. Coasting uses as much fuel as idle. Engine braking uses NO FUEL AT ALL for fuel injected cars. You will also save brake pads.

Lazarus

13-09-2011, 11:46 PM

True, not all Hondas are tuned for premium, but in regards to the OP's question 1.....comparing BP Ult/other premium fuels, speedway seems crap, but perhaps compared to other reg fuel it isn't too bad?
I know there's an independent fuel station on the great western hwy near maccas just past cumberland hwy intersection that is fairly cheap and has pretty decent mileage.

av90

14-09-2011, 10:59 PM

im filling up at about 135.00-145.00 per litre for 98 Pulp. 100% shell fuel. at local station.

getting good mileage, as good as bp/caltex....if not better i reckon.

Chriskoss

14-09-2011, 11:56 PM

Yes I know I am not measuring the fuel accurately. Most the time I fill up $20 worth at Speedway which gets me nearly half tank of petrol. But I find that Speedway Petrol seems to drain too fast, I drive around locally and I find that it just drains too fast hence I just filled up.

Where as one day I gave Caltex 95 Petrol a go only filling up $10 worth from an near empty tank and what I noticed It wasn't draining that fast as to Speedway. I could drive around a fair bit and I only filled up $10 worth.

That's why I am curious and asking what you guys think of Speedway petrol. Maybe it's the cause of my fuel running out so quick. If what I'm saying about Speedway is true, then I will need to find a better company to fuel up from. I just need someone to confirm.

Thanks!

Ok buddy there's your first problem.. how can 20 bucks get you almost half a tank?
Also the second half of a tank goes down in terms of the petrol needle on your dash faster than the first half..
But it will look like theres 1/2 a tank when really theres prob 1/4 to 1/3... 20 bucks would equal 14.5 litres at 1.40 a litre... your cars tank isnt 29 litres... most honda's are 45 litres to the brim so.. if you you think your not getting much out of half a tank its probably because its not really half a tank!!???

Why dont you fill up full next time with say 91.. and check the fuel economy with a fuel tank.. then do the same next week or 2 for 95? Why bother whinging when your only putting in 20 bucks at a time?!!

Lazarus

15-09-2011, 12:06 PM

Dang, good observation!
I wish i can get half a tank with 20 bucks....if only...

awaiken

15-09-2011, 08:58 PM

Why is everyone on this board against shell 98 PULP? I've tried all the 98's in town from Shell to BP, Mobil, Caltex and the independents and have found the most consistent to be V-Power 98. Only fuel that doesn't make my car shudder or leave black soot on my bumper. You can't just not recommend a certain fuel because your car doesn't like it, it's a trial and error system until you personally find one that you think/know your car operates better on.

I'd say try the higher octane fuels for sure though OP, you'll notices a bit more grunt and a smoother overall car with any premium fuel, the fine details are completely up to you! Grab yourself a bottle of Wynns/Nulon/etc injector cleaner and give that a run too, around $10-15 from any auto store. I get 400+ km's per tank on Shell 98 and I'm not exactly light on the throttle.

pat88c

15-09-2011, 10:55 PM

Why cry over a 20c different if will make your car run better, smoother and better fuel per 100kms than it worth it paying that extra per litre

But as other said before worth do engine tune up, replace spark, spark plug leads, fuel filter, air filter, and do throttle body clean
Will like cost few hundred in parts but will save you few more over 6-12 months
It will improve the car performance which in return will help give you better fue per 100kms

And doing O2 and water temp sensor is another great idea as sensors do age and wear

Glocker

15-09-2011, 11:15 PM

Shifting at 2000rpms? I've tried that before to save fuel and it just doesnt work. Because the sweet point of efficiency for most small capacity engines is between 2000 and 3000rpms, so the car has been underperforming and you most likely have to step on the gas hard to get to 2000rpm.