xrayangiodoc1

I tried to economize on fuel by using half premium (93 octane) and half regular (87 octane). I figured that the octane would average about 90 and be a better deal than the midgrade 89 octane fuel. The car seemed to run fine but after about a year I noticed moderate hesitation that required an injector cleaning by the dealer (under warranty) and the advice to stick to premium grade which I have since done. In regards to the winter driving issue (I live in the Buffalo, NY area), I put a set of Goodyear Assurance tires on and have been very pleased with the traction on snow. The tires seem to be very close to snow tire performance but are all-season. Wet weather performance has been excellent and the tire wear rating is about the highest I could find in a performance tire.

I owned a 1991 LS400 for 12 years. The timing belt change interval in MY owners manual was 60,000 miles, NOT 90,000 miles. When the dealer replaced the TB he also replaced the water pump and charged for it under the extended power train warranty. I just had the TB of my 2002 LS430 changed and at almost 90,000 miles the extended power train warranty was only a memory. The dealer was not automatically going to replace the water pump but I insisted on that. Also, the dealer was not going to change the serpentine belt for the accessories! I had then do that as well. I was already paying for them to remove and install those items so it just seemed to make sense to have those other major wear items replaced for just the cost of the parts!

Great Post! Could you provide the part number for the HID bulbs?

I see the same thing in a wide variety of electronics with temperature readouts. The ones that show tenths of a degree will jump by 0.9 degrees F (0.5 degrees C).

Does one need to go thru this procedure every time the car is started?

I have been using Synthetic oil since it first came out as Mobil 1. Have used it in all my Lexus vehicles (1991 LS400, 1995 RX300, 1998 RX330, and 2002 LS430) as well as my other vehicles and have never had a sludge problem. Always took the oil change interval to the max allowed. The synthetic oil is much more resistant to the high temperature breakdown relative to the standard motor oils. It also flows better in low temperatures (useful in the Buffalo, NY area). Probably also good for a little extra fuel economy.

Dirty fuel injectors might be contributing to this problem. I encountered similar symptoms on my 2002 LS430 which were cured after injector cleaning. Since then I pour a bottle of a good fuel injector cleaner into the tank before a long trip every few thousand miles. Also, don't try to save a few bucks by using half premium and half regular gas. Agree that the fuel filter should be changed if not done so as suggested in the maintenance schedule.