Is Premium Fuel Necessary For The Ls400 1992?

[JTom]

I'm looking very closely at buying a "parked in garage" in excellent condition LS400 1992 with 123,000 miles for about $6,500. One question though, I know it gets worse gas mileage but I'm going from a V6 Camry XLE that already only got 20-22, but do I have to have premium? No need for whatever power boost the higher octane gets, just don't want to damage my engine. Going to buy tomorrow morning or it might be gone so would love replies and thoughts soon if you got them!

Thanks :)

[chilkoot]

yes. running lower than premium can cause knocking (detonation) that can be very stressful on certain engine parts. some do run medium, but my old LS ran like crap with anything but 93.

also, make sure it's had the 100k service done or you're out another $1500-2000.

[JTom]

Damn that is too bad. With the price of gas these days I don't think I can afford that. Other people have the same thing happened using 87 octane regular gas?

[chilkoot]

Premium is always 15-20c more expensive than regular, so technically the higher the price of gas gets the less of a financial difference it makes whether you're running premium or not. you'll get about the same gas mileage you did with the corolla.

and a '92 isn't going to last very long at all if you run 87 in it. period. octane rating isn't about power, it's about stability. detonation is NOT a good thing.

[OmarG]

My boss has a 94 LS and is adamant about using regular. His car apparently runs fine. Personally though i still put premium. I don't wanna take a chance. Besides, i push my car hard so it deserves premium. Its a personal choice. I don't wanna sound rude but 20-30 cents is only $4-$7 bucks more per full fill up. I know gas prices suck but your better off driving less if you really want to save $$. Besides, regular will !Removed! timing and lower gas mileage. So you really save nothing in the end. if you fill up 4 times a month that only about 20-30$ extra a month.

I trust toyota engineers, so if they say premium I'm gonna put prem.

Chil you beat me to it. I guess i took too long.

[JTom]

Yeah that's true. And I just found out that USAA, at least from the quote from their website, drops my monthly insurance by like $60 a month. Have to see if I actually get it then but that should more than cover the price difference in premium gas and maybe even MPG between the Camry XLE 1997 V6. I dig the Camry but never liked the color (gold, the lexus is a nice dark green) and it has amazingly 70K more miles than the 120K miles on the 1992 Lexus ES400 I found.

So it's probably worth it, hopefully I'll be joining the club soon. :)

[SRK]

Hi JTom;

This is a topic well bashed in the past.

My 92 runs on 89 or 92, and my GS gets 92 only. Neither will ever "knock" because they have knock sensors that will adjust timing accordingly. And unless you are using full power, the octane isn't needed. You will not lose fuel economy using a lower octane, considering that if economy is important to you, you won't be using full power all the time. If I was street racing all the time, sure I'd use 94. Going to work I don't need it, and neither does the engine.

No commercially available gasoline will hurt these engines.

Now sit back, get the marshmallows, and watch the flames.....haahahahahahahahahahahahahahhhaha.....

[JTom]

Hi JTom;

This is a topic well bashed in the past.

My 92 runs on 89 or 92, and my GS gets 92 only. Neither will ever "knock" because they have knock sensors that will adjust timing accordingly. And unless you are using full power, the octane isn't needed. You will not lose fuel economy using a lower octane, considering that if economy is important to you, you won't be using full power all the time. If I was street racing all the time, sure I'd use 94. Going to work I don't need it, and neither does the engine.

No commercially available gasoline will hurt these engines.

Now sit back, get the marshmallows, and watch the flames.....haahahahahahahahahahahahahahhhaha.....

Wow, I felt reassured until that last sentence :P Sort of cryptic. Yeah I just drive to work, fairly steady...However uh, unsure if you were being sarcastic :) It's not much more I guess but if I don't need it, since I rarely go above 75 then I wouldn't. I like that the power is there if I need it but I'm getting the car for a smooth ride, reliability, safety, interior, and resale value.

[chilkoot]

Wow, I felt reassured until that last sentence :P Sort of cryptic. Yeah I just drive to work, fairly steady...However uh, unsure if you were being sarcastic :) It's not much more I guess but if I don't need it, since I rarely go above 75 then I wouldn't. I like that the power is there if I need it but I'm getting the car for a smooth ride, reliability, safety, interior, and resale value.

the flames he's referring to are a term we use for people who bash others needlessly.

regardless, I'd bet money that the '92 you're looking at still has the OEM plugs and wires, probably timing belt and water pump too. Don't pay a penny over $4k for that car unless you're absolutely sure everything down to the water pump has been replaced, with dealer records.

Also, there were significant changes made in '93, most notably bigger tires and brakes. That's the oldest you'll want to buy a used LS400 unless it's a super good deal (what you're looking at isn't).

[SRK]

Sorry for the confusion JTom, the last line does indeed as Chilkoot points out refer to the extensive bashing that went on some months ago when this kind of thread started.

As much as I like the 92, Chilkoot is also right that the 93-94's were a big improvement. I have experienced the undersized brakes of the 92 - I installed new factory rotors when I bought it used in 2003, and in three and half-years I turned them myself to remove a slight vibration. The 93's have huge brakes that never need turning it seems. My GS has perfect brakes and the rotors are original - not bad for a nine year old car.

But buying an LS is always a good thing. Best damn car on the planet. If I had the money I'd have five of them!

[JTom]

Wow, I felt reassured until that last sentence :P Sort of cryptic. Yeah I just drive to work, fairly steady...However uh, unsure if you were being sarcastic :) It's not much more I guess but if I don't need it, since I rarely go above 75 then I wouldn't. I like that the power is there if I need it but I'm getting the car for a smooth ride, reliability, safety, interior, and resale value.

the flames he's referring to are a term we use for people who bash others needlessly.

regardless, I'd bet money that the '92 you're looking at still has the OEM plugs and wires, probably timing belt and water pump too. Don't pay a penny over $4k for that car unless you're absolutely sure everything down to the water pump has been replaced, with dealer records.

Also, there were significant changes made in '93, most notably bigger tires and brakes. That's the oldest you'll want to buy a used LS400 unless it's a super good deal (what you're looking at isn't).

Thanks again for the pricing tip, it is in an amazing condition which is why I'm interested but I'll try and make them come down. Just some elderly person who lived literally blocks away from the dealership drove it and it's so pristine, I'm excited! :P I've been looking for a 93-94 as I read that model is definitely better but I can't find anything either A) with lower mileage under say 140K or B) under $8,500. Maybe they're more expensive around Austin?

But I'm gonna try and have them knock the price down even further, thanks! If I do get I'll report back with pics, already loving all the extra detail all over this forum!

[nc211]

I second SRK's comment about being the best damn car on the planet, almost to a fault. JTom, once you have one of these, it's really tough to replace them. Not that it's tough financially "personal situation", but it's tough to find anything that rides, drives, and feels as nice as the LS, for the price bracket. Just can't beat them. I know, I've tried and tried and tried again, and I just can't seem to find something I like as much. I've had an itching for a 5 series BMW lately, but one turn of the key, I hear the low rumbling of the exhaust, and I loose all desire for the BMW. I've grown use to the LS's quietness. So, if you ever want something else with a bit more sport to it, or utility to it, well, you might as well up that home equity line to build that third space in your garage, for your other car. THAT'S where these get expensive. You never want to get rid of it, so you have to add on to it.

The gas: I've run both, used 87 on the freeway a couple years ago on our way back up from Florida, and I felt a little slugglish, but nothing bad. However, and again just a personal opinion, I see the extra $30 a month for the premium stuff as preventive maintenence myself. I like the fact that it burns hotter, makes the engine smoother, and it is recommended for the car. I'm not quite sure what the compression ratios are for the LS, but I think they're in that range of needing higher octane. My dad's 85 500 SEL Benz I think is a 1:1 compression, which means it could practically run on water. But I think ours are a bit higher. Either way man, I would recommend the premium, just to be on the safe side of things. My 95 has 130k on the clock now, and other than that tank of 87 a few years ago, it's always been premium. I've never had an engine problem, ever. Had a leaking thermostat seal once, but that was it. Never has the car not started, never has it pinged, never has it stalled, never has the fuel filter clogged. The engine's mechanicals have never been a problem. Need a new serpentine belt, and that sort of junk, but the internals have never failed. I thank the premium gas for that. I drive 40 miles a day through back country roads to my office in Chapel Hill. I fill up 2 to 3 times a month, max. 130k miles and I still get 26+ a gallon. My car holds 18 gallons "fill up amount from when gas light comes on". For me, it's a price difference between $3.25 a gallon, or $3.00 a gallon, for a whopping $4.50 difference. I can't even get a 6 pack for that, or a big bag of Cheetoos!

My lawmower is one of those walmart $60 specials, Murray I think... Bought it nearly 4 years ago. I've always run premium gas in it, and it has always started on the very first pull, usually within the first 1/4 of the pull. I've never even changed the oil in the thing! Same goes for the weed trimmer, always used premium, and it too starts if I just look at it.

[wrpsuite]

94 ls 400 / 192k 18 mpg on mid grade with no problem...

[OmarG]

The 90-94 1uz-fe has a compression ratio of 10:1

Pretty high i think.

Right above the gas gauge it says, "Premium Unleaded Fuel Only"

There's much debate but to each his own. To me, the risk of lower performance and lower fuel economy is not worth the 5$ I'm saving. $60 fill ups already hurt my pocket so $65 doesn't make much difference.

I go by Manufacture Specs. I trust engineers the most.

[JTom]

I second SRK's comment about being the best damn car on the planet, almost to a fault. JTom, once you have one of these, it's really tough to replace them. Not that it's tough financially "personal situation", but it's tough to find anything that rides, drives, and feels as nice as the LS, for the price bracket. Just can't beat them. I know, I've tried and tried and tried again, and I just can't seem to find something I like as much. I've had an itching for a 5 series BMW lately, but one turn of the key, I hear the low rumbling of the exhaust, and I loose all desire for the BMW. I've grown use to the LS's quietness. So, if you ever want something else with a bit more sport to it, or utility to it, well, you might as well up that home equity line to build that third space in your garage, for your other car. THAT'S where these get expensive. You never want to get rid of it, so you have to add on to it.

The gas: I've run both, used 87 on the freeway a couple years ago on our way back up from Florida, and I felt a little slugglish, but nothing bad. However, and again just a personal opinion, I see the extra $30 a month for the premium stuff as preventive maintenence myself. I like the fact that it burns hotter, makes the engine smoother, and it is recommended for the car. I'm not quite sure what the compression ratios are for the LS, but I think they're in that range of needing higher octane. My dad's 85 500 SEL Benz I think is a 1:1 compression, which means it could practically run on water. But I think ours are a bit higher. Either way man, I would recommend the premium, just to be on the safe side of things. My 95 has 130k on the clock now, and other than that tank of 87 a few years ago, it's always been premium. I've never had an engine problem, ever. Had a leaking thermostat seal once, but that was it. Never has the car not started, never has it pinged, never has it stalled, never has the fuel filter clogged. The engine's mechanicals have never been a problem. Need a new serpentine belt, and that sort of junk, but the internals have never failed. I thank the premium gas for that. I drive 40 miles a day through back country roads to my office in Chapel Hill. I fill up 2 to 3 times a month, max. 130k miles and I still get 26+ a gallon. My car holds 18 gallons "fill up amount from when gas light comes on". For me, it's a price difference between $3.25 a gallon, or $3.00 a gallon, for a whopping $4.50 difference. I can't even get a 6 pack for that, or a big bag of Cheetoos!

My lawmower is one of those walmart $60 specials, Murray I think... Bought it nearly 4 years ago. I've always run premium gas in it, and it has always started on the very first pull, usually within the first 1/4 of the pull. I've never even changed the oil in the thing! Same goes for the weed trimmer, always used premium, and it too starts if I just look at it.

Thanks man! I dug my Camry as well, about to hit 191K miles and I'm sure it would have gone another 60K but wanted a change of pace. I think I will go premium or midrange since it isn't a huge difference.

[chilkoot]

I have experienced the undersized brakes of the 92 - I installed new factory rotors when I bought it used in 2003, and in three and half-years I turned them myself to remove a slight vibration. The 93's have huge brakes that never need turning it seems. My GS has perfect brakes and the rotors are original - not bad for a nine year old car.

But buying an LS is always a good thing. Best damn car on the planet. If I had the money I'd have five of them!

Next time you feel like your '92 needs it rotors turned try doing some hard braking. Sometimes it's just pad deposits built up on the rotors and heating them up will fix the issue. This is especially true if you're really easy and gradual on the brakes, which one is inclined to do driving a car as smooth as the LS.

[GKLCPA]

I'm looking very closely at buying a "parked in garage" in excellent condition LS400 1992 with 123,000 miles for about $6,500. One question though, I know it gets worse gas mileage but I'm going from a V6 Camry XLE that already only got 20-22, but do I have to have premium? No need for whatever power boost the higher octane gets, just don't want to damage my engine. Going to buy tomorrow morning or it might be gone so would love replies and thoughts soon if you got them!

Thanks :)

I always run premium in my car just to be on the safe side.

I own a 98 Nissan Maxima and the recommended fuel is premium, but I've always used regular. The car currently has 180K miles on it and has never had a problem with the engine.

[lexus082]

Lexus isn't making any money off of what grade gas you use. So, when they say to use a certain octane grade its best to go with that to avoid any problems. I use the Exxon 93 and no matter how much I hate paying the extra for the gas I will b/c thats what is recommended with the 1UZFE engine.

[chilkoot]

Lexus isn't making any money off of what grade gas you use. So, when they say to use a certain octane grade its best to go with that to avoid any problems. I use the Exxon 93 and no matter how much I hate paying the extra for the gas I will b/c thats what is recommended with the 1UZFE engine.

it's worth it, if only for peace of mind.b

[Vern Dias]

Your Lexus will definitiely run on regular grade, but here is my experience with 2 different Lexus vehicles:

1998 LS400 (CPO):

Filled the tank with regular, 2 tank fills later, I needed to accellerate heavily to avoid being hit by another car. Floored it, and: Ping City!!!!!

Also, I noticed performance was relatively poor with poor gas milage. Went back to premium for the 5 years I owned the car.

Took a trip from Texas to Colorado to Montana to Oregon, and back to Texas. 5000 miles, typical freeway speeds of 70 to 80 MPH, fuel economy for the entire trip: 31 MPG.

2004 LS430 (CPO):

Drove it home from the dealer. The car seemed sluggish. Milage on a freeway run of 30 miles at 65 MPH was roughly 24 MPG. I was not particularly impressed with the car.

2 tanks of premium gas later, car was much peppier and a freeway run netted me 32 MPG.

So yes, you can use regular. Will it save you any money? IMHO, No it won't because the fuel economy will be considerably poorer with regular.

Just my $.02

Vern

[wwest]

Ain't technology, MODERN technology, wonderful...!

Back in the days of carburators and NO knock/ping sensors and NO microprocessors engine timing was the ONLY variable that could be adjusted for fuel grade.

Nowadays we do have knock sensors, very capable microprocessors and guess what?

FUEL INJECTION.

If you put low grade fuel, within reason, into a modern day engine the sensors will detect any resulting knock/ping and the microprocessor will then adjust, enrich, the mixture via fuel injector "open" timing to overcome the "problem". Net result, lower fuel economy but no engine damage.

When I picked up my 2001 Porsche C4 at the factory I was told that the only thing I had to be careful about in my travels throughout europe was to ALWAYS fuel with unleaded. When I asked how that could be I was told the above.

Makes sense.

[RFeldes]

I also tested lower octane on my 90 ls400 and found the loss of fuel economy was not worth it. I think I came up with a savings of around $3 per tankfull using premium.

[92silverls400]

Your Lexus will definitiely run on regular grade, but here is my experience with 2 different Lexus vehicles:

1998 LS400 (CPO):

Filled the tank with regular, 2 tank fills later, I needed to accellerate heavily to avoid being hit by another car. Floored it, and: Ping City!!!!!

Also, I noticed performance was relatively poor with poor gas milage. Went back to premium for the 5 years I owned the car.

Took a trip from Texas to Colorado to Montana to Oregon, and back to Texas. 5000 miles, typical freeway speeds of 70 to 80 MPH, fuel economy for the entire trip: 31 MPG.

2004 LS430 (CPO):

Drove it home from the dealer. The car seemed sluggish. Milage on a freeway run of 30 miles at 65 MPH was roughly 24 MPG. I was not particularly impressed with the car.

2 tanks of premium gas later, car was much peppier and a freeway run netted me 32 MPG.

So yes, you can use regular. Will it save you any money? IMHO, No it won't because the fuel economy will be considerably poorer with regular.

Just my $.02

Vern

I agree with you 100% I had a 92 LS400, tried using 87 octane, had bad gas mileage, and the car ran bad. instead of filling up once a week, had to fill up twice aweek. premium gas here in california is $3.60 per gal (SF bay area) will always use premiun gas for my 00 LS400

[GKLCPA]

Your Lexus will definitiely run on regular grade, but here is my experience with 2 different Lexus vehicles:

1998 LS400 (CPO):

Filled the tank with regular, 2 tank fills later, I needed to accellerate heavily to avoid being hit by another car. Floored it, and: Ping City!!!!!

Also, I noticed performance was relatively poor with poor gas milage. Went back to premium for the 5 years I owned the car.

Took a trip from Texas to Colorado to Montana to Oregon, and back to Texas. 5000 miles, typical freeway speeds of 70 to 80 MPH, fuel economy for the entire trip: 31 MPG.

2004 LS430 (CPO):

Drove it home from the dealer. The car seemed sluggish. Milage on a freeway run of 30 miles at 65 MPH was roughly 24 MPG. I was not particularly impressed with the car.

2 tanks of premium gas later, car was much peppier and a freeway run netted me 32 MPG.

So yes, you can use regular. Will it save you any money? IMHO, No it won't because the fuel economy will be considerably poorer with regular.

Just my $.02

Vern

I agree with you 100% I had a 92 LS400, tried using 87 octane, had bad gas mileage, and the car ran bad. instead of filling up once a week, had to fill up twice aweek. premium gas here in california is $3.60 per gal (SF bay area) will always use premiun gas for my 00 LS400

Premium in CA is 3.60??? I thought I had it bad paying 2.93 in NJ last week which is about 10 cents cheaper than the price here in PA. The fuel taxes makes up at least 30-40 cents of PA's price and I imagine that must be much worst in CA.

CA is nice, but I don't see how people can afford it between gas prices and real estate prices. NJ/NY is pretty bad on the real estate measure as well.

[menappi]

That's the pricey ou pay for luxury. I've heard the premium gas actually gets you better gas mileage so it ends up kind of evening it self out.