I did not expect the compression to be as high as 10.5:1. Factory timing may already be rather mild so if the ECU retards even further to compensate for 87octane it may venture into the less efficiency realm. 89 octane isn't too bad, doesn't have as much crap as the higher octane "pump" fuels. The new LS460, 11.8:1, good Lord.
Regular or Premuim as the debate continues?
- Thread starter jibbby
- Start date
The 1UZFE EGR Delete Kit is available for sale here.
spf_lexus
Active Member
Nice thread, always wondered about some of these questions. I have owned my LS for 4 years and always ran premium. One pleasant surprise was when I re-built my heads. I popped both banks off and it was obvious where the coolant washed 2 f the cylinders clean but overall I had NO deposits. I mean except for the 2 cleaned ones they were gold on top, no visible layers of anything and I feel that has something to do with the persistence of premium. Brake cleaner would not take anything off the pistons because there was nothing to take off!!
Once I left on my 1200 mile trip to college I averaged 30mpg at 60-65MPH on open highway with cruise control on most of the way and new load of royal purple synthetic oil. I was clocking 450-500miles per tank, that was the most efficient trip the engine ever held and she was on the road 2 hours after bolting everything back together.
I feel that 1uz can be run with reg if the user wants, I have done it before but in N/A it drove like a dog! and got slightly worse mileage because i was adding a heavier foot to compensate for the lower power. If you run good oil and good intervals I see no probem with regular, (unless FI then god have mercy on you :hail
Once I left on my 1200 mile trip to college I averaged 30mpg at 60-65MPH on open highway with cruise control on most of the way and new load of royal purple synthetic oil. I was clocking 450-500miles per tank, that was the most efficient trip the engine ever held and she was on the road 2 hours after bolting everything back together.
I feel that 1uz can be run with reg if the user wants, I have done it before but in N/A it drove like a dog! and got slightly worse mileage because i was adding a heavier foot to compensate for the lower power. If you run good oil and good intervals I see no probem with regular, (unless FI then god have mercy on you :hail
stevechumo
Active Member
I always run premium on all of my cars, although the cars are Honda, Camry, or this SC400. I see a big difference (better) in starting the engine, smoother idle, more gas saving, and a little bit more power response than 87 octane. If I pour a bottle of Slick 50 (injector cleaners) and fill with 91 octane, the car runs so smooth. In fact, when I tried 87 in my previous turbo Honda, it knocked so freaking bad. This is my experience. You may have other experiences, but well, you may risk what you might have avoided.
