this post was submitted on 27 Aug 2026
288 points (94.2% liked)

Fuck Cars

16520 readers
776 users here now

A place to discuss problems of car centric infrastructure or how it hurts us all. Let's explore the bad world of Cars!

Rules

1. Be CivilYou may not agree on ideas, but please do not be needlessly rude or insulting to other people in this community.

2. No hate speechDon't discriminate or disparage people on the basis of sex, gender, race, ethnicity, nationality, religion, or sexuality.

3. Don't harass peopleDon't follow people you disagree with into multiple threads or into PMs to insult, disparage, or otherwise attack them. And certainly don't doxx any non-public figures.

4. Stay on topicThis community is about cars, their externalities in society, car-dependency, and solutions to these.

5. No repostsDo not repost content that has already been posted in this community.

Moderator discretion will be used to judge reports with regard to the above rules.

Posting Guidelines

In the absence of a flair system on lemmy yet, let’s try to make it easier to scan through posts by type in here by using tags:

Recommended communities:

founded 3 years ago
MODERATORS
 

What's a little extra 5 or 10 mph on the clock?

you are viewing a single comment's thread
view the rest of the comments
[–] jafffacakelemmy@mander.xyz 9 points 2 days ago* (last edited 2 days ago) (3 children)

I tested my car as a hypermiler over thousands of miles on dead flat roads empty of other vehicles, my daily commute was 78miles. The most economical speed was 30mph in 5th gear with cruise control on. For most people that's not a practical speed for any kind of long journey,but I was getting over 100miles per uk gallon in the summer (hot weather helps with fuel economy, as does not having headlights or ac on). I got through so many audiobooks driving so slowly!

[–] boonhet@sopuli.xyz 2 points 1 day ago (1 children)

Hot weather does not help with fuel economy precisely because you have to turn on AC (or arrive at your destination a sweaty mess, everyone will LOVE that smell).

Mild weather helps a lot with fuel economy though, engine still warms up faster compared to the winter and you don't need AC.

The most economical speed was 30mph in 5th gear with cruise control on

That can't be too good for your engine's health unless you have a fairly short 5th gear (e.g if you have 6 or more gears anyway or just a short final drive). Most of my manuals have been 5 speed manuals and they aren't too happy in 5th at 50 km/h.

Since you mentioned below that it's a diesel, that will cause real issues over a few hundred thousand. I had to clean turbo vanes on a 415k km 1.9 tdi, all gunked up from eco-driving. Vanes don't get exercised and they don't get any proper heat either. You'd ideally want to be cruising around 2000 rpm and you should be using most of your rev range, not just the bottom end.

[–] AA5B@lemmy.world 1 points 23 hours ago

Seriously, that’s why I always just accepted the approximation of 45mph …. The lowest speed you can smoothly drive in the top gear.

But you can hear when the engine is going too slow, when you’re potentially causing more harm than good. Anyone using a standard transmission knows where their shift points are and intentionally going significantly below that is counterproductive

[–] cyclonedusk@lemmy.blahaj.zone 2 points 1 day ago* (last edited 1 day ago)

ooooh ... you know what, maybe i'll avoid highways and stick to roads with 30 mph speed limits, too, actually. i drive a hybrid so it might be pretty chill and cost next to nothing.

[–] sukhmel@programming.dev 4 points 1 day ago (1 children)

If you don't mind sharing, what car is that, and what year of manufacture?

[–] jafffacakelemmy@mander.xyz 5 points 1 day ago

A Skoda Fabia Estate Greenline Diesel 1.2 litre engine, made in 2011. I took it past 180,000 miles until a deer jumped out and put and end to things.