47
votes
9answers
11k 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 ...
43
votes
9answers
7k 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 ...
39
votes
15answers
135k views

Should I resurface or replace my rotors everytime I replace brake pads?

I have heard it is proper practice to replace or resurface your brake rotors every time your do a brake pad replacement. Does this need to be done every single time or is it overkill? Maybe it is ...
37
votes
13answers
51k views

Does Downshifting (Engine Braking) Cause Extra Wear and Tear?

Does the act of downshifting to slow your vehicle down have any negative side affects? I don't downshift more than one or two gears at a time and I let out on the clutch slow enough that I don't rev ...
36
votes
7answers
3k views

What to check when buying a used car?

I'm looking to buy a used car. What do you think I should check (mechanically) before buying it (especially if it's diesel)?
35
votes
5answers
1k views

How to maintain a sometimes-used vehicle?

My daily commute changed from 9 miles to 9 feet when I started working remotely. That means I very rarely drive my car much. After a particularly hectic month, I didn't drive for about 4 weeks and ...
33
votes
5answers
37k 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 ...
30
votes
4answers
75k views

Why does my A/C blow foul smelling air when it first turns on?

Most of the time when I first turn on the A/C in our 2008 Toyota Sienna, the air that blows out has a very distinct chemical - nasty smell. After a while it seems to go away. I'm not sure if I just ...
25
votes
3answers
9k views

Reviving a vehicle that has been idle for a long time.

Some related topics: How to maintain a sometimes-used vehicle? How long does it take for gas to go bad? The first related topic addresses preparing a vehicle for long-term disuse, and maintaining ...
25
votes
3answers
14k views

Is there a way to put Prius with dead battery into neutral?

I own a 2010 Prius. It has a dead battery, front facing forward in my garage. I do not have long enough jumper cables. I’ve searched the Internet. Did Toyota really create a car that cannot be put ...
24
votes
3answers
5k views

Difference between FWD/RWD/4WD/Part-Time 4WD/AWD?

I'm curious as to what are the particular difference between the various drive systems available in modern vehicles. FWD and RWD are pretty straightforward - Front Wheel Drive cars put the power to ...
22
votes
5answers
2k views

Is tire rotation important?

I just bought new tires for my car and included was free tire rotation every 7,500 miles for the life of the tires. I have heard many things about tire rotation, including: it's a worthless ...
21
votes
2answers
3k views

Do I have an oil leak if I have to add oil?

I don't change the oil all that often (maybe every 8000 miles) and on my 10 year old car the oil light comes on and I need to add a quart or two (and then I start thinking I practically changed the ...
20
votes
4answers
16k views

How far can I drive with 1 gallon too much oil?

I have way too much oil in my Acura TSX. Do I need to take care of it without turning it on or can I drive it to a service station? If I need to do it in place, I don't have the ramps or a pan or ...
20
votes
8answers
18k views

Is it necessary to 'burn in' or 'break in' a new car?

I've just bough a new 2011 plate car. I've heard stories of people 'burning in' engines for the first few hundred or couple thousand miles using methods such as: Not driving above 50 mph. Varying ...
20
votes
8answers
30k 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 ...
20
votes
2answers
1k views

How to deal with rust

I accidentally drove my car over a curb a while back. As you probably already know, the car suffered from minor scratches and dents on the bottom side, near the rear tyre. Now, I've noticed that it's ...
18
votes
6answers
34k views

Pros/cons of higher capacity car battery?

I'm shopping for a new car battery for 1998 Subaru Outback (2.5l). For the physical dimensions the battery has to match, I see some variance in capacity (Ah) rating, and in price too, of course. The ...
17
votes
6answers
123k views

what is the difference between DOT3 and DOT4 brake fluids?

What is the difference between DOT3 and DOT4 brake fluids? What could possibly go wrong if I use a (4 times cheaper) DOT3 brake fluid instead of the DOT4 which manufacturer recommends (but allows ...
16
votes
2answers
4k views

Jump starting a dead battery: Connect black wire to negative pole of battery or grounded metal?

Most of the advice I've seen for jump starting cars instructs to connect the black wire to a bare piece of metal on the car with the dead battery. However, I've always just hooked up both poles to the ...
16
votes
1answer
5k views

Why does the reverse gear in manual transmission cars sound different

When I got a manual transmission car (2003 Kia Rio) I noticed that it makes a winding sound in the reverse gear. Here is an example video that I found that demonstrates the sound. ...
15
votes
10answers
158k views

How should I remove a paint scuff on my vehicle?

The painted edge of a side mirror on another car recently scraped the side of my vehicle, leaving a scuff of paint about half a meter long. There is no indentation or scratch, but the other vehicle ...
14
votes
11answers
64k views

What happens if a single spark plug unexpectedly goes down in a multi-cylinder engine?

AFAIK vehicle manuals say owner must replace spark plugs every N miles. Suppose he fails to do so and a single spark plug unexpectedly dies in an engine with multiple cylinders right in a freeway. ...
14
votes
4answers
8k views

Is Start & Stop technology good or bad for my car? (Alfa MiTO)

I was recently in the lucky position to obtain an (almost brand new) Alfa Romeo MiTo, Progression. Like many new cars coming out these days, it has "Start & Stop" technology that turns the engine ...
13
votes
11answers
24k views

Wheel stuck or fused to drum

1997 Chevy 1500 My right rear wheel is stuck or fused to the drum. I can get the lugnuts off, but no luck getting the wheel off. I took it to a tire place and they couldn't remove it either, and said ...
13
votes
2answers
4k views

Why doesn't the engine stall out when you come to a stop with an automatic transmission?

When you come to a stop with a manual transmission you have to push the clutch in or take it out of gear to keep the engine from stalling out. What keeps the engine from stalling in an automatic ...
13
votes
4answers
52k views

What's the point of the D3 gear in an automatic transmission?

My Honda Civic has a D gear and a D3, which apparently prevents it from going into 4th. Why would I want to do this? What is it good for? Does it make my fuel efficiency better or worse? Does it ...
13
votes
5answers
26k views

What is the best way to remove a stuck/rusted exhaust bolt?

I'm trying to disassemble the exhaust system on a 2000-2003 nissan maxima and I'm having trouble removing one last bolt.. its got a 14mm head and its just plain STUCK. I've tried soaking it overnight ...
13
votes
3answers
857 views

What does a water-like drop coming out of the exhaust of the car signify?

Sometimes while driving in the traffic, I come across a car or two which would be dripping water-like drop from it's exhaust steadily in a break of 4-5 seconds. I tried to ask a couple of people at ...
13
votes
4answers
26k views

What are the risks of overfilling a small engine with oil?

I recently overfilled a 4 stroke lawnmower engine with oil. It has been run for about 1.5 hours while overfilled. It smokes a lot right after being started but after 30 seconds or so the smoke clears. ...
13
votes
3answers
3k views

Static vs. Effective compression: Why does higher effective compression not require higher octane gas?

Background I've been trying to do a lot of research on boost lately because I'm planning on running a moderate turbo setup on my daily/light-duty-autox car in the future. I'm trying to get into the ...
13
votes
4answers
2k views

Is downshifting on hills harmful for non-trucks? [duplicate]

Possible Duplicate: Does Downshifting (Engine Braking) Cause Extra Wear and Tear? Since the days of taking drivers ed (many years back). I was told that when you encounter a steep or ...
13
votes
7answers
3k views

How old is too old for a new tire?

When shopping for new tires from tirerack.com, the production date of the tires is listed. I'm considering tires from a 2007 production run, which would make them around 5 years old today (after ...
12
votes
4answers
1k views

The headlights dim to almost off when I turn off the engine. How do I test the battery?

My car still starts fine but when I turn off the car (just the motor . . the key is still in and "on") I noticed the headlights dim to almost off. It's and older car and the headlights don't turn off ...
12
votes
6answers
30k views

Running with straight water as coolant in the summer. Is it fine?

I grew up flushing the coolant twice yearly. In the Spring, you drain the antifreeze and fill with straight water for the summer. In the Fall, you drain the water and put in a 50/50 antifreeze/water ...
12
votes
4answers
10k views

Driving in second gear at 65+ mph

I accidentally drove my 2000 Grand Marquis on second gear on the highway. I was going 65 for like 5 minutes and tried to get it to 70mph but the car was shaking, when I realized I put it into regular ...
12
votes
3answers
3k views

Is it worth switching to full synthetic or blend oil in my older car/truck?

I have a older (enter vehicle here) that has 100k miles on it. Would I see any benefit switching to full synthetic or synthentic blend oil? Is it worth the extra cost in an older vehicle? For ...
12
votes
5answers
14k views

Is it safe to drive a car that has got a broken suspension spring?

Yesterday I was driving home from work and heard a loud noise which I can only really describe as a "clang". After looking at it today, it looks like the spring for the front left (passenger side) ...
12
votes
1answer
2k views

How do I know when to change my spark plug

I ride a Piaggio scooter with a single cylinder engine. Recently I broke down and the engine wouldn't restart. It turned out the spark plug was stuffed. How can I ensure that doesn't happen again?
12
votes
3answers
888 views

What is the proper way to bleed brakes and replace the fluid?

What is the proper way to replace the brake fluid in a car? What tools are required? I want to make sure I do not get any air or bubbles in the system as this is something that needs to be done right ...
12
votes
2answers
301 views

How To Get Organized Without a Garage Workspace?

People I've seen who have garages have it made. They have a clean, dry workspace with all of their tools within arms reach. In the most organized garages, a mixture of rolling Snap-on Roll Cab with ...
12
votes
2answers
2k views

What is the technical reason the engineer decided the motorcycle gear pattern as follows?

The gear pattern is selected by clicking a lever with your left foot, and is typically laid out as follows: 6th gear (if applicable) 5th gear 4th gear 3rd gear 2nd gear NEUTRAL 1st gear What ...
12
votes
2answers
8k views

Is starting your car with the A/C on bad?

I was always yelled at by my father when I was first starting to drive when I left the A/C on when I turned off the car, and then later turned it back on, with the reasoning that I was ruining / ...
12
votes
1answer
5k views

Is Anti-Seize a lubricant, abrasive, or both?

I'll flesh my personal bias at the outset - being a heavy diesel mechanic for a time, and mechanically inclined my entire life, I use Anti-Seize wherever I can. If it has threads and it's not part of ...
11
votes
9answers
24k views

How can you tell the oil needs to be changed?

I know oil should be changed every 3000 or 6000 miles (depending on the car and conditions) but I'm not all that great at keeping track and I've let the car go for 10,000 miles before and it still ...
11
votes
6answers
16k views

How far can you drive with an empty radiator?

The radiator on my Peugeot 106 has started leaking very badly and need replacing. I don't have time to fix it at the moment, so I'm taking it to a garage. How far can I drive it without damaging the ...
11
votes
5answers
2k views

Adding a additional battery to car

I have purchased a brand new Toyota Innova. I need to install a a mac mini, 2 laptops and make this car a mobile office. I need to know if I can install another car battery in parallel, and will ...
11
votes
5answers
3k views

How to fix leaky tires after 2 shops couldn't

I have an SUV with factory 16" steel wheels and P235/70R16 tires. The tires have just under 30,000 miles of gentle driving on them. Two of the tires have been leaking quite a bit (about 10 psi per ...
11
votes
5answers
2k views

My Car Squeals When Braking Even Though I've Had My Front Rotors Machined and Back Rotors Replaced and all new brake pads. What could it be?

I own a Toyota Soarer SC300 (1994), 2JZ motor non-turbo 3 litre engine. The engine is probably irrelevant, but provided for prosperity. Anyway, the front rotors were machined and are within the legal ...
11
votes
6answers
9k views

My car's coolant temperature reaches almost 100 C / 212 F in a fast pace

Today, after a very hot day, I saw that my coolant was almost reaching 100C/212, I pulled over, stopped and took a look over the hood. The very little water that remained in the coolant tank was all ...

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