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Apr
6
comment Do cars consume less fuel when in Neutral?
It's a clear dupe of "Is shifting to neutral on a decline more fuel efficient than keeping the gear engaged?", but it really is not a dupe of "Will engine braking damage my transmission? How can I tell?".
Apr
6
comment Do cars consume less fuel when in Neutral?
@nocomprende Perhaps it's for manuals only, and maybe some select auto boxes. But I don't know much about pulse and go other than it's occasional usage in hypermiling, so can't say for sure.
Apr
5
comment Do cars consume less fuel when in Neutral?
@JasonHutchinson right I see that now, doesn't even specify the grade or whether you're braking. I can't see major issues with rolling in-gear if you're within the speed limit and you aren't using brakes, but hey, lawmakers.
Nov
25
comment How does cold, dry weather affect horsepower?
Hey Munga83, thanks for your response and welcome to Mechanics.SE! FYI you'll need to clean up some of your grammar and spelling, otherwise your answer could get flagged.
Oct
24
comment How can I empirically evaluate the condition of my used motor oil at home?
You can do basic light spectroscopy for cheap - I've used a simple ~$50 tool for measuring alcohol content (home-brew). Obviously you could spend millions on this endeavour, but I'm wondering if a basic, sufficiently-effective approach could be achieved for a reasonable sum.
Sep
25
comment How long can I keep motor oil for before it needs to get put in the car or thrown out?
How about if it's been opened? As what I'm thinking of is those larger containers for a more "buy in bulk" price.
Jul
6
comment Does “slogging” an engine (open throttle at very low RPM) increase mechanical wear?
Ah I didn't see that question, don't think it came up in the Related questions list. Should I delete this, or leave it as is to serve as a link redirection?
Jun
27
comment How does cold, dry weather affect horsepower?
Interesting point. Though I think humidity is a different case, as it's in gaseous form then, not droplets of liquid.
Jun
25
comment How does cold, dry weather affect horsepower?
Great, so it looks like I indeed have a free cold air intake! Would be fascinating to see if super cold temps, like -40C, continue to make a big performance improvement. I'll have to take my car to Antarctica to find out...
Jun
25
comment BMW 530xd e60 2008 diesel engine turns but won't start
Was there any resolution to this? Or is the car still not starting?
Jun
3
comment Do fast cars need to occasionally be driven fast?
True, ideally the engine should just be pushing out CO2 rather than soot. Might not always be the case with some engines, and those might benefit from a fiery soot-cleaning, but that then changes this question to "Do fast, poorly tuned cars need a good fanging?". Thanks for all the info!
Jun
3
comment Do fast cars need to occasionally be driven fast?
Ah fascinating. Ok so it makes sense that an engine running at operating temperature is a happy engine - no need to fang it. Last point - how about the exhaust? Some cars have monstrous exhaust pipes (GT-R) to handle the exhaust from a 600 BHP+ engine, and my understanding of back pressure says that you'd get carbon buildup from driving well below the max power output. Would this be the one case where an Italian Tuneup is helpful?
Jun
2
comment Do fast cars need to occasionally be driven fast?
Ah right, so would that mean that harder driving doesn't require the radiator (fan) to work significantly harder?
Jun
2
comment Do fast cars need to occasionally be driven fast?
Interesting, nice to have an anecdote. And yes, I'm realising that there isn't substantial objective knowledge about this. That forum unsurprisingly includes people advocating spirited driving for engine maintenance, but again, the bias is heavy! I'll let this question hang for a bit longer to see if we get some more objective responses.
Jun
2
comment Do fast cars need to occasionally be driven fast?
Good answer. I guess the uncertainty lies around the "operating temperature". Yes you have the cooling system temp, though for a given cooling system temp my understanding is that you could have a significant range of temps of the engine internals. I think it's possible that the engineers could design an engine for which the proper operating temperature, for internal carbon buildup prevention, is actually quite hot due to "spirited driving". I'm still learning about mechanics, but would that be reasonable?
Dec
10
comment Engine power specification at different rpm?
Great explanation. Do you prefer the peaky curve even just for street driving, or is it mainly because you track your car?
Dec
4
comment Assuming identical and sufficient ABS, and ignoring aerodynamics, are tires the only factor for braking distance?
@BobCross Yep I hope I portrayed that by showing that µ isn't constant. Ok to try make it really clear, I mean a braking system which is overpowered. The pads and pistons and all that have more than sufficient force to slow down the wheels as much as they want - so much so that they could lock the wheels, but due to the use of ABS they don't lock the wheels, they instead grip at the threshold. I don't get why you're saying the cornering grip and braking grip is completely unrelated - didn't you read the "Traction Budget" from The Physics of Racing?
Dec
4
comment Assuming identical and sufficient ABS, and ignoring aerodynamics, are tires the only factor for braking distance?
@mac Exactly, that's what I wanted the answer to contain. Check out the answer I wrote up, do you think it's reasonable?
Dec
4
comment Assuming identical and sufficient ABS, and ignoring aerodynamics, are tires the only factor for braking distance?
@BobCross Not a problem if you don't agree with the edits, I'll just draft up something myself.
Dec
4
comment Assuming identical and sufficient ABS, and ignoring aerodynamics, are tires the only factor for braking distance?
@BobCross I did some more research, and Wikipedia (en.wikipedia.org/wiki/Tyre_load_sensitivity) and other sites (technicalf1explained.blogspot.com.au/2012/10/…) explain that the coefficient of friction decreases slightly as load increases. This explains everything in my mind - your experience of higher mass resulting in slightly worse braking, and even the nose dipping doing likewise. I'm going to draft some edits on your answer incorporation this, hopefully we can come to an agreement.