Originally Posted by jimsaq

weird, this is the complete opposite to my experience in every diesel I've driven, which exhibit far greater engine breaking than gasoline engines I've driven. I'd always assumed it was due to the compression ratio


in my nissan patrol for example, I can drive 60k's from my house to the office in normal traffic and only use the brakes 5 times in total where an intersection or traffic lights require it - this is because when I stop accelerating there's a LOT of engine braking. I can't even come close to the same type of low brake useage in my wife's jeep wrangler. both vehicles are manual transmissions.


even in my X5 which is a 3.0sd which obviously has an auto transmission, there's quite a bit of engine braking going on because the transmission is often smart enough to change down for me on descents and even flats under certain conditions. I noticed the difference quite starkly between both the 3.0d/3.0sd and the gasoline 4.8 when I took them for test drives.


another example with the nissan again - I have 85% reduction gears in it (low range only) and my friend with the gasoline engine has the same gears, along with the same transmission and diffs. on really steep declines, the type where you need the seatbelt to stop you sliding into the dashboard, his vehicle will gather more speed than mine despite mine weighing far more.