Higher-Octane Gas Could Improve Fuel Economy

[Caleditor]

The highest octane pump fuel sold in the USA is either Propane or CNG. I was at the fuel station I get E85 from, filling my Titan at $2.85 a gallon for 104 octane E85. While filling the tank I looked over and the CNG pump was $2.25 GGE. Sometimes I wish I were running natural gas.

I have been known to install CNG kits and work on them from time to time. I am even a certified inspector. I love my CNG.
Local filling station is $1.58 GGE and it is 130 octane. The CNG does displace some of the volume of air entering the cylinders, but it is also about 17 to 1 AFR.

Take a look at the 2015 Impala CNG. the company the is building this car does it right, nit some patched together junk like the 2013 C2500 were.

Anyway back to the subject. The major automotive establishments want HIGH OCTANE. I think they have plans for high compression to make the engines more efficient.

Way back when I was doing my training at the tech college I think the optimum ratio was taught to us was around 15 to 1 compression ratio. Of course in a lab or on a dyno. I think the best RPM was around 2000. Now this is all very old information and information evolves, so I would guess that it is all out dated.

I sure would like to see 13+ to 1 compression ratio with good fuel and direct injection. I think it would help elevate the particulate issue with the direct injection engines. It looks like they are going to have to add particulate filters to gas engines

[Fast355]

I have been known to install CNG kits and work on them from time to time. I am even a certified inspector. I love my CNG.
Local filling station is $1.58 GGE and it is 130 octane. The CNG does displace some of the volume of air entering the cylinders, but it is also about 17 to 1 AFR.

Take a look at the 2015 Impala CNG. the company the is building this car does it right, nit some patched together junk like the 2013 C2500 were.

Anyway back to the subject. The major automotive establishments want HIGH OCTANE. I think they have plans for high compression to make the engines more efficient.

Way back when I was doing my training at the tech college I think the optimum ratio was taught to us was around 15 to 1 compression ratio. Of course in a lab or on a dyno. I think the best RPM was around 2000. Now this is all very old information and information evolves, so I would guess that it is all out dated.

I sure would like to see 13+ to 1 compression ratio with good fuel and direct injection. I think it would help elevate the particulate issue with the direct injection engines. It looks like they are going to have to add particulate filters to gas engines

Hopefully adding particulate filters to a gasoline engine would not murder the efficiency of it.

[RobertISaar]

mazda has 13:1 direct injection with gasoline now..... and getting some pretty impressive MPG numbers in the mazda6, which isn't a small car. i want to say with 87 octane as well.

[Caleditor]

mazda has 13:1 direct injection with gasoline now..... and getting some pretty impressive MPG numbers in the mazda6, which isn't a small car. i want to say with 87 octane as well.

The complete design is well worth looking at. I love how they dropped the NOX in that engine.

[steveo]

i love mazda for the weird concept designs that they just chuck into production vehicles, most other car companies try new stuff and never get out of the concept car stage... wankels.. miller cycle.. crazy direct injection setups..