Crf Hf Sil?
 

I did a search for MPG rating on www.fueleconomy.gov for a 91 CRX HF and to show up one is SIL. The SIL gets better MPG but what is SIL?

SIL= shift indicator light :) I believe.

Shift Indicator Light on Instrument Panel. Click on the link next to SIL on the site and it will give you a run down on what the abbreviations are.

"for a 91 CRX HF and to show up one is SIL. The SIL gets better MPG but what is SIL?"

eh? Don't understand your sentence, "...and to show up one is SIL".

The only thing I can imagine is that you're asking why the HF shows up under the EPA reports' MPG rating as having two different ratings. IF this is your question, here's the deal:

The HF came in two different trims (High Altitude / Low Altitude), or 49-state model / California model, if you prefer that language. The High Altitude model has a shorter final drive ratio (i.e. shorter 5th gear) to make power in, um, high altitudes. The Low Altitude model has a really tall 5th gear / final drive. This is the reasoning for the EPA's CRX HF listing as being both 43city/49hwy MPG versus 49city/52hwy MPG.

Not sure what to be more embarrassed about the bad grammar or the fact I searched the site and did not see I could click on "Trans Characteristics"

So basically they are saying is people are to stupid to know when to shift without a light.

Maybe I should start paying attention to my SIL. I always shift before it has a chance to come on.

No. I think what they were attempting to do was to help people who normally rev the engine/transmission pretty high, to shift at a more optimum point, for mileage. In your case, you are probably already shifting at or before that point, so the light is a stupidity light, but eh, at least it's available.

On the HF transmission, I'm a little confused. I know their are the two versions which Brian described, but if I look on carparts.com, they also list a high altitude version transmission, as well as the 49 state version and the ca version. Does anyone have any idea of what the differences are?:(

I sorta thought that EPA would shift when the light told them to, if it was present. Otherwise, they would shift when they felt like it or when their protocol dictates. So two identical cars (except for the SIL) could have different EPA estimates.

Ok so people are not stupid the EPA employes are.

I know this is an old thread but since I found it via google, I think I should clarify a few things..

Firstly, if you find two models and one has SIL next to it and the other doesn't but otherwise they appear mostly the same, then the distinction is usually whether the car is a "federal" or "california" car. When I say "Federal" or "California" it refers to the emission's standard to which the car has to abide by. At least for Hondas, the "federal" cars come with an SIL (Shift Indicator light) and the "California" cars don't come with an SIL. I have no idea behind their reasoning except it does help with differentiating between the vehicles.

If you care about mileage, follow the SIL light. There are limited circumstances where not following to the light is beneficial, one of them being anticipating traffic, road anomalies, grades (up or down hill) or signals. For the most part though, you want to follow the light because at least for Hondas, the light is not strictly based upon RPM but also on load, if you're driving with a light load, it'll come on sooner and with a heavy load, it will come on later. I haven't definitively proven this (since I don't own a vehicle with one) but it'd be useful if there was some testing for fuel economy as to whether or not following the light or simply shifting earlier improves mileage or not.