About gasoline, diesel and other fuels.

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44
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8answers
9k views

What are the benefits of premium (high octane) petrol?

Here in the UK it's common for petrol (gas) stations to offer both regular and "premium" unleaded petrol. The premium stuff is (naturally) more expensive, and I've often wondered what the actual ...
41
votes
9answers
5k views

Does the amount of fuel in the tank matter?

As long as there is some fuel in the tank, does the fuel level matter? In other words, is it advisable to make sure the tank is mostly full most of the time, or is this just silly? In other words, are ...
30
votes
5answers
27k views

How long does it take for gas to go bad?

Approximately how long does it take for unleaded gasoline in the tank and fuel lines to become unusable in a car that is not being used? What causes this, and what can be done to prevent or remedy ...
19
votes
8answers
22k views

Will higher octane fuel improve gas mileage?

I've heard from some people that high octane fuel will increase gas mileage. Around here, we have the basic unleaded(87), mid-grade(89), and premium(93 or 91). I've been using the basic 87 unleaded ...
10
votes
6answers
6k views

How to properly dispose of old fuel?

I have some old 2 stroke mixed gas I need to get rid of. This could also apply to old fuel removed from a sitting car or any vehicle for that matter. What is the proper way to dispose of this? Are ...
9
votes
7answers
7k views

Diesel vs Petrol motorcars. Pro's and cons?

I realize this may be a silly question to those of you on here who are proper petrol-heads and this may even be a repeat question, but I could not find anything on it on here, so here goes: What are ...
9
votes
5answers
4k views

How to improve fuel economy in high-mileage car?

I'm driving an 2003 Acura TL 3.2 with 177K miles on it. I bought the car with 110K miles on it. It seems to me that the car is not getting the same fuel economy that it did when I acquired it. I ...
9
votes
3answers
6k views

How do I safely siphon gas from a tank?

Our 2003 Windstar was recently totaled in an accident (everybody's ok). This happened the day after we filled the tank. Before we hand over the car to the insurance, we'd like to get the fuel out of ...
9
votes
1answer
2k views

how to optimize fuel consumption by changing the rear differential ratio?

Is it possible to improve the fuel consumption (decrease it) in my van by changing the rear differential ratio? I would like to optimize it for low-speed driving about 40 km/h (25 mph). Is it true ...
7
votes
3answers
1k views

Cleaning fuel injectors?

I took my car (2006 Honda Civic) to firestone to get an oil change and they told me I should get the fuel injectors cleaned. I was in an Advanced Discount Auto Parts store the other day and I noticed ...
7
votes
1answer
519 views

how can I measure the amount of fuel injected into a diesel engine in real time in a purely mechanic pre-OBD vehicle?

This is a Mercedes-Benz 308D van, year 1992, model 602.316. Pre-OBD, no electronics of any sort, everything is purely mechanical. I would like to retrofit a system which would measure the precise ...
6
votes
2answers
8k views

Why should the fuel petcock valve be turned to “Off” position when not using the vehicle?

It’s mentioned in the user manual of my motorbike, that when not using the vehicle, I should turn the petrol tap (the one that has three positions “On”, “Off” and “Reserve”) to “Off” position. I don’t ...
6
votes
4answers
970 views

Subsitute for Leaded Gas

I have an old '73 240-Z that I am fixing up in class. Once I get it running, will I need to add something to the gas? I know that old cars ran on leaded fuel, the lead lubricating the parts as it ...
6
votes
3answers
3k views

Is high octane fuel a requirement for high-compression engines?

I own and use a 2005 Chrysler Crossfire SRT-6 as my daily commuter vehicle. I'm not interested in trying to eek out a few extra miles on a tank, I want to keep the vehicle and its engine running as ...
6
votes
2answers
15k views

Are fuel system cleaners (like Gumout) worth using regularly?

Are fuel system cleaners (like Gumout) worth using regularly?
6
votes
2answers
3k views

Test Gasoline for Water Content

I live in a small town, and the Gas station there has a bad reputation for gas quality. With rumors like peoples gas tanks freezing solid and such. Is there a quick, safe, cheap way to test for ...
6
votes
2answers
562 views

Power loss in truck - triage options?

I've asked at least one question about my specific situation earlier, but at this point, I'm looking for information on how to operate in triage mode, my primary goal is to get my truck working well ...
5
votes
2answers
1k views

How to know how much fuel is left when the light turns on

In general, where can one find information about the quantity of fuel that is left in the vehicle's tank when the warning light turns on? More specifically, in a Suzuki Swift GLX (auto) 2010 model?
5
votes
4answers
744 views

How to tune the ECU / fuel trim in a custom-built engine

I have a Gen VI 454 in my Suburban that needs some work. I'm thinking about turning it into a 496 stroker. Once I find a list of mechanical components (crank, cam, pistons, heads... everything) that ...
5
votes
5answers
12k views

Racing Fuel (100 Octane Rating) - Better than Premium?

Earlier today while driving out East on Long Island I stopped to fill my tank with gas, and at the station, all the pumps had the usual Regular, Mid, Premium on one pump, but on the 2nd pump which ...
5
votes
4answers
217 views

Is it even possible to buy gasoline anymore that does not contain ethanol in the US?

I can't remember the last time I went to a gas station and it didn't have a notice that the gas contained some quantity of ethanol. As I understand it, ethanol is harder on my engine than regular ...
5
votes
1answer
1k views

Difference between high octane and low octane?

What is the difference between high octane and low octane fuel? I'm not asking if one is better than the other for my vehicle, specifically, but rather what occurs differently both scientifically and ...
5
votes
3answers
135 views

I'm looking to buy a new car and I'm wondering what does more damage on a car: time or miles?

So the title is pretty self explanatory. I'm looking at getting a minivan, and there is a 2011 model with 50k miles, and a 2008 model with like 30k miles. What's better? Is it better to have ...
5
votes
2answers
171 views

Is it okay to run aviation fuel (100 low-lead) in a dirt bike?

I'm wondering if it will be okay to run 100 octane low-lead aviation fuel in my 2007 RM250 motocross bike (two-stroke). Half of the people I've asked say yes, while the other half say no. Will it be ...
5
votes
2answers
891 views

Car is sluggish, jerking and idles rough.

I have a VW Polo Classic, 1.6L. Just recently it started to be slightly jerky when in idle and whilst driving. There is also a loss of power, a strong fuel smell, and sounding slightly like a VW ...
5
votes
2answers
209 views

1993 Jeep stalls on acceleration, floods, hard to start

My 1993 Jeep Wrangler has about 200,000 miles, in good shape. It usually starts right up, but it's started intermittently flooding, so that I have to crank and crank with the accelerator all the way ...
5
votes
3answers
87 views

Is the fuel in my engine under pressure?

I have a 2008 Seat Leon FR TDi and need to change one of the fuel pipe (which has become torn slightly). The hose is ~ £50 + VAT so I am keen to do it correctly. Can anyone advise if the fuel in my ...
4
votes
4answers
733 views

Does the tachometer provide any indication of fuel usage?

So, I'm driving along on the highway with the A/C blasting when I notice the price of gas. It makes me think, "what can I do to increase my fuel efficiency?" Some of the tips I've heard have included ...
4
votes
7answers
4k views

When given a choice between octane 89 and 93, which should I choose?

I just recently got a 2005 Volvo S40 with a turbo engine; I want to take good care of it, so naturally, when the instruction manual recommends 91 octane fuel but says it takes a minimum of 87, I have ...
4
votes
2answers
138 views

Proper fuel for motorcycles?

I've heard that regular petrol (92 octane ULP) from some fuel companies is not good for motorbikes as it is intended for cars only. Is this just an old wives tale?
4
votes
1answer
847 views

Is there a standard for how much fuel is left in the tank when the meter reads empty?

I know this question is very similar, but I am specifically talking about the fuel gauge and not an indicator light. Almost every car I've owned could run for quite a while with the fuel gauge reading ...
4
votes
2answers
3k views

Why does my engine perform poorly and get bad gas mileage after using fuel injector cleaner?

At the advice of someone at a local auto parts shop, I poured a bottle of fuel injector cleaner into my gas tank. This happened around the same time that I had a brake job done and rotated my tires. ...
4
votes
2answers
660 views

2010 Toyota Corolla - pumping gas - the gas pump kicks off constantally

In another forum someone said "Screen down the fillneck may be partialy plugged up with matter." Is this something a neophyte can change or fix himself, or should I take it to an auto shop? How can I ...
4
votes
1answer
399 views

1997 Geo Metro dies after driving for a short time. What next in diagnosing culprit

Back Story: I recently took my Geo Metro on a road trip. 2700 miles of road trip. The first 800 mile nothing happened. Then going up a hill it died, dropped from 75 mph to 55 mph then the engine ...
4
votes
1answer
186 views

Fuel leaking out of drain tube

I just purchased a 1985 Suzuki gs300l. When I put gas in the tank it immediately started pouring out the drain tube that is connected to the air box. What is wrong and how can I fix it?
4
votes
1answer
111 views

2003 Ford Escape..strong fuel smell

2003 Escape 3.0L V6 149,000 miles 4x4. Three weeks ago a very strong fuel smell coming from rear of vehicle after I park it. Don't smell it anywhere else. Replaced the original fuel cap with after ...
4
votes
2answers
632 views

Can I use lower octane fuel at high elevation?

Here in Colorado, gas stations sell "regular" gasoline which is rated at 85 octane ((M+R)/2). In most of the rest of the US, 87 octane is the lowest grade available. (As noted previously, higher ...
3
votes
2answers
331 views

What is E85 gasoline and how can I avoid it?

My new mower says not to use E85 gasoline. What is E85 gasoline, why should I avoid it, and how do I know if I'm buying it?
3
votes
5answers
587 views

2007 prius premium gas or not?

I have a 2007 prius with around 125000 miles. my mileage dropped about a year ago. I had the fuel jets cleaned, but it didn't really make a difference. the dealer shop said it probably was the ...
3
votes
1answer
453 views

Add 2 stroke oil to a 4 stroke petrol engine during burn-in period

I'm planning to get a new petrol (gasoline) car soon. A friend of mine, who worked as a motorbike mechanic when he was young, told me he puts a small quantity (125 ml / 4 oz) of 2 stroke oil in the ...
3
votes
2answers
708 views

Marine Diesel fuel filter vacuum gauge spiked — filters are new

I've got an 80-HP marine diesel engine (in a sailboat, naturally). I've got a the Parker/Racor 75500MAX dual fuel filter system with an attached vacuum gauge to monitor resistance. For the first few ...
3
votes
1answer
1k views

Is it possible to use biodiesel in a BMW 335d if I remove the DPF and remap the ECU?

The new (2009-current) BMW 335d sells in the U.S. with a DPF to reduce emissions, but which prevents the use of biodiesel. I've read about people removing the DPF and re-mapping their ECU to get ...
3
votes
2answers
24 views

1987 Ford Ranger fuel gauge not working right

My fuel guage will work but when it gets to half a tank it will drop to empty with in a few minutes but still has gas in it.
3
votes
1answer
44 views

Should I run my generator dry in preparation for storage?

I think this is on-topic after reading the FAQ, so I figured I'd go ahead and ask. I gave my gas generator its scheduled 3-month interval "workout" last night, and after letting it run for about 30 ...
3
votes
3answers
526 views

Is it feasible to Turbo a NA engine while maintaining 87 AKI octane fuel use?

I initially thought there should be a way to bolt on a small aftermarket turbo onto my naturally-aspirated Honda D17A2 (9.9:1 compression ratio) engine in my EM2 Civic EX without having to switch from ...
3
votes
2answers
90 views

What will happen if there is something else also with petrol in car

Today someone broke my car fuel outer case and taken out fuel. I came home by driving but then i have now one doubt in my mind. What if he put something else in tank like water, sand, etc in there. ...
3
votes
1answer
57 views

Why wasn't my engine getting fuel?

This is a 1975 Ford F-350. It has been sitting idle for 6 months, and is rarely used. Normally, when I try to start it after sitting for a long time, it takes a bit of cranking before it starts. I ...
3
votes
3answers
3k views

Determining how many miles can be covered on full tank [closed]

I'm interested in the following cars, but the questions apply equally well to any car: Audi TT Lexus IS 200 (SE or not?) I'm finding it difficult to determine the following: How do I figure out ...
3
votes
1answer
99 views

2000 Honda Civic Dead Fuel / Temp Guage

I am having a problem with the Fuel / Temp Guage on my 2000 Civic. I just bought the vehicle second hand, it came with the original Dash Cluster and another one swapped from another civic, which ...
3
votes
1answer
158 views

Cleaning a Jerrycan

I have a couple of 10 Litre steel jerrycans which I used for draining kerosene (UN1223 28sec burning oil) from a tank. After disposing of the kerosene I left the open jerrycans upside down over some ...