Steve wrote: Agave wrote: It's more cost effective for the manufacturer to include a tach in all models where a tach would otherwise be an option. But there are many models that don't offer ANY manual transmission option AT ALL, and yet they have tachs.
In keeping with my prior opinion, consider not just a specif model, but also...
"similar" models, for example the Taurus and Sable as well as the Canadian, European, and other market varieties internationalization of auto manufacturers, for example Ford and Mazda - the Probe and MX-6 cross model pollinization a US model may not offer a manual transmission, but an international market model may
I'd argue that very few people actually need a tach, regardless of transmission type. As others have pointed out, with most new cars/trucks having rev limiters, a tach is a "nice thing to watch", but not very useful, as well as how many people and how often does one red line their engine.
I think you can blame market research, focus groups, product testing, grabbing a piece of the after market pie, business decisions (e.g., "I'll give you a deal on 10 million fuel gauges, if you buy 3 million tachometers."), and just the general American mind-set of wanting things you don't really need for the reasons why there are tachs in cars with automatic transmissions.
At this point though, I think most people would notice that they didn't have a tach...even though they might not have a clue what it does :). I commend you for noticing just the opposite and questioning the meaning of things.
Now, if someone can tell me why people don't use their cruise control, I'd be interested.