SCdriver

If you change your oil every 3,000mi you can use regular penzoil purebase oil or other high quality regular oil. If you change oil every 5,000+mi, I would use mobil 1 synthetic. I use lexus or nippon or advantex or wixx oil filters. Don't skimp on quality when it comes to oil filters. I also put in NGK iridium spark plugs and am very satisfied with them. I have a ram fx foam air filter but don't think they are available anymore so you should check other responses for advice on air filters.

If you leave your car locked with the alarm on and with the auto sensor for the door locks etc., you can drain even a new battery in a couple of weeks. So, whatever battery you buy (I have an interstate) if you don't use your car for moderate or long periods of time invest $45 in a schumacher battery tender that maintains your charge but turns off automatically to prevent sulfation.

If you go with a newer SC why not try a '98 where you get the 5 speed auto and VVT 290 hp engine which are the only significant upgrades from the original in my opinion. If you keep your older car, try putting in a can of RESTORE and using mobil one on your next oil change and it should even out your compression unless you have a major problem. Otherwise, if it ain't broke why fix it?

I replaced my OEM plugs with NGK iridiums and they work fine. I increased my mpg on long highway trips approx. 1-2 mpg. If you shop around you can get them for $6-8/plug and they should last 80,000 mi+.

If you keep the stock rims keep the stock sized tires. I put Goodyear Eagle GS D3 F1 ultra high performance tires on my Sc400 and they are terrific. They stick like glue and are very quiet. Check tirerack.com and go through their selection process. I gave up some tread wear for performance and am very happy with these tires. They are also great in the rain.

The best tire depends on what your needs are and what compromises you want to make in terms of wear, performance and weather ratings. The best tires I've owned (and I've had high performance tires from most major brands) are the ultra high performance Goodyear Eagle GS D3 F1's. They stick like glue in the wet and the dry and are very quiet. I expect the soft compound will not have super long tread life but it is worth the trade off for the added saftey and comfort.

There are two Sc cars on Ebay being parted out. Check under automotive parts and SC400 and see if they have any of the parts you need.

Check Ebay for nackamichi amps for the car and other items as they are listed from time to time. You can also try a search engine for salvage parts. Good luck

If you want an automatic transmission go with the SC400. Get a lexus dealer to go over the car as their inspection only costs approx $90. Get their service history and the car fax history. Watch out for a leaking power steering pump common at 80-100,000mi and the usual wear items----shocks ,brakes, tires, hoses etc. Since the AC is the old freon type (pre 1994) check to make sure it doesn't have leaks as it can be expensive to change to R34a... Good luck

I use NGK iridium plugs. You can get them for about the same price as the bosch and they are cheaper than denso iridiums and will give the same performance and should last 100,00 mi. You should be able to find them for $7-8/plug. Try a search engine for them or yahoo or ebay.

There are not many tire choices for the 17" rims and if you have a lot of potholes or do city driving 18" rims can easily be damaged. I kept my original 16" rims and put on Goodyear GS D3 F1 ultra high performance tires. This was the best upgrade I have made. They are very quiet and stick like glue in dry and more importantly wet conditions. Unless you autocross or must have the look of the larger rims you can get similar performance at much less cost by getting these tires or similar performance rubber. Check out the reviews and cost (and possible rebates) at tirerack.com.

Try checking Ebay. Go to Auto parts and accessories and then search under SC400 and you can usually find some listed. Otherwise you could use a search engine. Good luck...

Try tirerack.com and go through their questions for the type of driving you do. I have Goodyear GS D3 F1 Eagle tires on the original 16" wheels and they stick like glue in wet or dry conditions and are very quiet. Save yourself the expense of new wheels and go for better tires.

You have listed a number of upgrades but since you are keeping the OE wheels you should consider upggrading your tires when the time comes... I have Goodyear Eagle GS D3 F1 tires purchased from tirerack and they are by far the best wet and dry performance tire I have owned. They are also very quiet . That is the best upgrade for the money I've made on my SC400. You should also consider NGK iridium plugs, mobil one oil with lexus, nippon, or advantex or wixx filters and an upgraded air filter. To get any real increase in low end engine performance, you will need to spend a fortune and consider a torque converter replacement &/or supercharging etc. which in real world driving may not be worth the expense.

Check out tirerack.com and go through their decision guide for your type of driving. Dry & Wet handling etc is always more important than ride noise etc. I have Bridgestone RE950 tires on my '95 Ls400 and they perform much better than the OE tires at only $98 each. You can get even better tires now for just a bit more as they are trunniing a clearance on the very highly rated (and quiet) Firestone Firehawk SZ50 EP tires at $115 each and the Michelin Pilot sport A/S which run about $136 each after rebates. I'd try the Firehawks as they are a lot of tire for the money. You can call and discuss your options. I've bought my tires from them for over 20 years without a problem.

I get my oil filters etc from the-best-source.com and they have a good selecton of parts for most lexus models. Check out their website------

Before buying an SC400 have it inspected by a Lexus dealer for Approx. $90 and get the lexus service history from them and the carfax history. Pre 1994 cars will have old freon AC systems which can be expensive to properly change to R34a. For cars over 70,000 mi check for the ususual power steering pump leak. For cars near 90,000mi or over make sure the timing belt service was done. Expect to replace the fluids,filters and brakes and check the tires and you are on your way....

I get 24-27mpg on long highway trips. I have NGK iridium spark plugs, a Ram FX foam filter, properly inflated Goodyear Eagle F1 tires and use chevron techron fuel additive every 6,000 miles and keep the overdrive button on the shifter on to improve highway mileage. City driving mileage is 14-17mpg. I use Mobil one oil and nippon or advantex oil filters. If your mileage is very low check to see that your overdrive is on which decreases your rpm at highway speeds and try adding 20 0z of techron fuel additive when you fill your tank to clean your intake ,valves and injectors.

Get the lexus service record and carfax record. Get a certified lexus inspection for around $90 and see what the car needs. If it has 75,000+ miles the power steering pump could start leaking. If it is pre 1994 it will use R12 freon and proper conversion to R34a is expensive and freon is hard to come by at a reasonable price. Check the usual wear items:shocks/struts, brakes, rotors, tires and expect to change all fluids and filters--oil,coolant,brake,etc.

You should check tirerack.com as they have rated tires for dry and wet performance as well as ride comfort and quietness. I would not make a decision mostly based on how quiet a tire is as wet handling etc is more important. Go check out the website and fill out the questonaire for the type of car and driving you do and you can compare several tires and reviews.

Tirerack.com has always given me good advice. If you want to save a small fortune (the cost of 4 or 5 new wheels) and still get super performance you can stick with the original wheels and go for much better tires. I got the Goodyear Eagle F1's and they are very quiet for an ultra performance tire, ride well and stick like glue.

Come to think of it---the sc430 has run flat tires so you probably can't flat spot them as easily as regular tires by having them sit in one place for months. So I would just check with lexus regarding battery charging or disconnecting it etc.

You might try putting it on a schumacher battery tender that keeps a full charge automatically but doesn't overcharge. Or if it won't be moved you can ask Lexus if you should disconnect the battery and how that will effect the stereo and computers etc. However, I would consider having it moved once in a while to avoid flat spotting the tires and getting a good but not too expensive car cover. Depends on whether you can trust someone in your garage to look after it ................

You should be getting 25-27mpg if you were driving on highways with little traffic at the speeds you mentioned. If your gas milage was lower, try puttng in some techron fuel additive before the next trip and run nearly the full tank and make sure your plugs are OK and you have a relatively new air filter etc. I get 25-27mpg on long highway trips. Enjoy your car......

Try tirerack.com for advice and good prices. I have Bridgestone RE950's on a 95 LS400. Excellent in the dry and rain. I use more performance oriented tires for the SC. Go through the tirerack questionaire for the type of driving you do or give them a call. I have always gotten good advice from them and unlike some other reports in the forum, the people I have dealt with there over the last 20 years have always been professional and polite.