I noticed that it can be confusing when selecting a engine type for your car. For example look at the 2012 Honda Civic, the choices for engine type are CNG, GAS, GAS L4, GAS H4. I think H4 stands for the hybrid, then why not just call it Hybrid. What about L4, does that actually mean "Inline 4"? If there is no v6 why would that matter, just call it gasoline or petrol or I4.
People with the LX, EX, and HF models are split between GAS, and L4. There is an HF owner who listed his car as a H4.
I think the best way to avoid this is to list cars that have different drive-trains by themselves just like the Civic Si models are. The Civic HF, and the Civic Hybrid should have their own separate group for better comparison and to avoid corrupting data and confusion.
We don't want to get into parsing the various trim levels of different models. Trim designations for many models can be more marketing than meaningful, and we're trying to keep things very simple. Here's more of our thinking on keeping things simple: Why don't you track more vehicle details?
As for the HF owner confusion, yeah, that's going to happen in a system where users report their own data. Sometimes people will get it wrong. We can't have 100% accuracy so we have to live with some things like this. That doesn't mean we can't be continually working to make things more clear for people. We are thinking about these issues.
There is one thing relating to this which could be helpful - when browsing a vehicle model, you can filter by (for example), petrol, petrol L3, petrol L4, diesel, diesel L3, and diesel L4 (in the case of my Audi A2, it is only actually produced in a 3-cylinder version).
However (if I remember correctly), filtering by Diesel only shows you the cars entered as diesel and not diesel L3 and Diesel L4. It would be handy to have a 'diesel-all' and 'petrol-all' option so that it merges the diesel-with-unspecified-cylinders, diesel-L3, and diesel-L4 together into a single list (for my vehicle, all three versions are actually referring to a single 1.4 L3 engine in real life - although there are two horsepower levels, 75 and 90).
In the UK at least, people are more likely to know their engine displacement (1.4 vs. 1.6 vs. 2.0) than their cylinder count. This is because engine displacement used to be the key figure for the annual car tax payment. I don't know if the same observation applies in different countries.
It doesn't. Here in the U.S., most states only have you pay tax once, when you first buy the car/plates. Then all you have is a plate renewal cost each year after that. Some states go by the type of vehicle when calculating the plate fees, other states go by the value of the vehicle when it was new.
None of them really care about what size the engine is, or its displacement. And I would about bet that most of the erroneous entries are from U.S. vehicle owners here.
Why not just use the EPA (for US, Euro, Japan, etc) designation? For the 2012 Civic it would be: CNG, Hybrid, HF, 1.8 Auto, 1.8 Man, 2.4 Man, or so. Might work especially since those designations are based on MPG and people are using fuelly.com for MPG. Helps with filtering too.
The EPA only indexes US vehicles. And one of the things we're trying to accomplish with Fuelly is making things friendlier and easier to use than the EPA. If people are confused or intimidated by the choices, they'll leave. So we don't want to bombard them with acronyms and options. We want folks to say, "oh, Honda Civic, that's what I have."
Like I said, our engine definitions don't fit into this ideal. So we have some work to do there. But I think the EPA descriptions are a step backward from what we have.