When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Its not your choice, running them on lower spec fuel makes the engine CONSTANTLY micro knock and the computer reel back timing and creep it back up until it gets out of range again......then your rings fail and you start eating oil. I sent you plenty of links explaining knock control strategies and you can literally easily check to see if you LX is pulling timing from fuel with ease.
Just put a scanner on it and see what the KCLV is.
It's not "lower spec fuel" though, or if it is it's lower spec fuel for every 5.7. This is what I don't get y'all don't get.
ODB Scanner? I have one of those.
You do realize the unnecessary resources and especially the cost to tune or build the 5.7 differently just for the LX would be significant, right? It's the same damn engine that went into every Tundra lol, just built in Japan alongside LC.
The LH cars were surprisingly good. My Grandfather ordered a Concord when they were brand new before they came out and it was a good car, never any trouble. I'm not a Chrysler person but I did like that car. It had the base 3.3 pushrod which was much less powerful but felt just as good and torquey as the optional larger 3.5L.
The engine is the same, but the tuning is different. That's why the LX570 hp peak is 2hp higher than the LC, and more importantly why there is a LOT more area under the torque curve. So a properly-fueled LX is going to feel more responsive in "normal" driving situations than the LC, despite being ~200lbs heavier.
I have not seen hp/torque curves for an LX570 running on 87, however, so I can't say to what degree it will be less responsive than the LC on 87 as a result of the computer having to pull a bunch of timing.
Originally Posted by AJT123
No, it's because the truck doesn't need it and I hate wasting money, not spending it. It's stupid to me to put premium fuel in a vehicle that doesn't need it. I'm not going to be a sucker. If it needed it, I'd use it. I hattttte wasting money, that's what it is.
LX and LC were built alongside each other in Japan with the exact same V8 engines put in. You really think Lexus engineers would waste money for more than 2hp and change stuff on the assembly line, spend money on big tune difference? The 5.7 was plenty sufficient to move the LC and LX around. Not the fastest kid on the block, but quick enough. The engines are IDENTICAL. Ask any head Lexus tech if the 5.7 needs premium.
There are plenty of cars that actually do lose a decent amount of power on regular (but run fine) but the automakers specify it's fine to use it. Premium gives those said cars a hp boost, or regular takes it away--your choice. In this situation with the 5.7, it's a whopping 2 horsepower. LXs are fine on regular, it mitigates the awful mileage whereas all the other high end SUVs actually do require premium. The Yukon costs an insane amount to fill up lol. It's still worth it though.
Our LX has always had premium and it’s never seen 12mpg. Heck I got better than that towing my car on U-Haul trailer with the LX. I was impressed how well it towed.
I may try premium in the Tundra next time I’m towing the trailer to the track. I’m heading home averaging 6.7mpg on this tank so far. Lots of hills.
AJT123, if that era LC/LX are both fine running on 87, why does Lexus recommend 91 for the LX570?
also, while you might be saving 'per gallon' at the pump, i would not be surprised if you're getting worse fuel economy on 87, and if so, you might well be wasting money which we know you haaaaate.
i think you should do a test of each, and for each, fill, record start mileage, drive a bunch, record mileage and refill, not how many miles to refill, and calc mpg.
The LH cars were surprisingly good. My Grandfather ordered a Concord when they were brand new before they came out and it was a good car, never any trouble. I'm not a Chrysler person but I did like that car. It had the base 3.3 pushrod which was much less powerful but felt just as good and torquey as the optional larger 3.5L.
They are pretty cool cars to see nowadays.
Originally Posted by geko29
The engine is the same, but the tuning is different. That's why the LX570 hp peak is 2hp higher than the LC, and more importantly why there is a LOT more area under the torque curve. So a properly-fueled LX is going to feel more responsive in "normal" driving situations than the LC, despite being ~200lbs heavier.
I have not seen hp/torque curves for an LX570 running on 87, however, so I can't say to what degree it will be less responsive than the LC on 87 as a result of the computer having to pull a bunch of timing.
I agree with you. I wonder if the 5.7 in the tundra is truly certified for the rating or is it without all the peripherals. Toyota used to rate the HP prior to 2005 with the use of premium and no accessories attached. I don’t think any other Toyota has the same ratings across multiple models. There is a Land Cruiser in UAE with the 5,7 and 362HP. So I have always wondered it the US 5.7s are dialed back to that.
I heard a modern BMW will log non-91 octane and void the warranty. But I am not sure
IMO, every Toyota I have driven feels to run just a little sharper with 91. I hade always perceived their 4 cylinders to be less rattle less when pushed hard. I just looked at what the ES250 4 cylinder requires and it’s 87 or higher. Why do they emphasize or higher?
I bet this is the case for every single Toyota. They just leave the premium fuel part out
Last edited by Toys4RJill; Jul 14, 2024 at 07:47 PM.
The LH cars were surprisingly good. My Grandfather ordered a Concord when they were brand new before they came out and it was a good car, never any trouble. I'm not a Chrysler person but I did like that car. It had the base 3.3 pushrod which was much less powerful but felt just as good and torquey as the optional larger 3.5L.
I had an Intrepid company car the same color as the one in the ad. It was a pretty good car, well equipped for a company car.
It's not "lower spec fuel" though, or if it is it's lower spec fuel for every 5.7. This is what I don't get y'all don't get.
ODB Scanner? I have one of those.
You do realize the unnecessary resources and especially the cost to tune or build the 5.7 differently just for the LX would be significant, right? It's the same damn engine that went into every Tundra lol, just built in Japan alongside LC.
I have the same engine as you on factory tune that is not as aggressive as the Lexus one. Mine pulls 10* timing on 87 vs 93.......
I agree with you. I wonder if the 5.7 in the tundra is truly certified for the rating or is it without all the peripherals. Toyota used to rate the HP prior to 2005 with the use of premium and no accessories attached. I don’t think any other Toyota has the same ratings across multiple models. There is a Land Cruiser in UAE with the 5,7 and 362HP. So I have always wondered it the US 5.7s are dialed back to that.
I heard a modern BMW will log non-91 octane and void the warranty. But I am not sure
IMO, every Toyota I have driven feels to run just a little sharper with 91. I hade always perceived their 4 cylinders to be less rattle less when pushed hard. I just looked at what the ES250 4 cylinder requires and it’s 87 or higher. Why do they emphasize or higher?
I bet this is the case for every single Toyota. They just leave the premium fuel part out
Funny thing about that is I have some older ESs and Avalon's in my care and they all gain 5-7mpg and more power off 93 octane. Some of that I'm sure is due to the old knock sensors overacting, but the higher octane removes all of the timing pull.....
The one car I have that I know never pulls timing is the Jeep, since it can't. No knock sensor so it's full send no matter what fuel
Last edited by Striker223; Jul 14, 2024 at 08:03 PM.
I believe in 2015 Lexus said you can run 87 in the RX 350 and I believe the horsepower lowered -5 from previous years. 275 to 270 I believe going from 91 to 87.
I believe in 2015 Lexus said you can run 87 in the RX 350 and I believe the horsepower lowered -5 from previous years. 275 to 270 I believe going from 91 to 87.
What about the midrange? You know very well knock becomes far less of a factor at higher RPM and outputs relative to load.
AJT123, if that era LC/LX are both fine running on 87, why does Lexus recommend 91 for the LX570?
Because it's their flagship truck and cost about $100,000, it's just marketing. I can't think of any other vehicle that expensive that officially takes regular.
Originally Posted by bitkahuna
also, while you might be saving 'per gallon' at the pump, i would not be surprised if you're getting worse fuel economy on 87, and if so, you might well be wasting money which we know you haaaaate.
.
No, like I've said I have a heavy foot and get about 12 city, but 14MPG city is attainable if you seriously baby it.. 20MPG highway is easily attainable.
Because it's their flagship truck and cost about $100,000, it's just marketing. I can't think of any other vehicle that expensive that officially takes regular.
No, like I've said I have a heavy foot and get about 12 city, but 14MPG city is attainable if you seriously baby it.. 20MPG highway is easily attainable.
‘But what are they marketing?
Toyota literally tells you in the manual that your LX will run better with premium fuel. And Toyota even alludes to 94 octane as providing even greater performance
Last edited by Toys4RJill; Jul 14, 2024 at 08:23 PM.
What about the midrange? You know very well knock becomes far less of a factor at higher RPM and outputs relative to load.
I will run 93 in the truck to next track day and see how she pulls and mpg. I’m willing to try it. I remember exactly what I averaged and how far a tank took me.
I should’ve tried 93 just now as I stopped to refuel. I pulled 35 gallons into a 38 gallon tank. Right now all I’m thinking about is blower!!
The dreaded V35A does tow better!! Especially on hills. Blower on 5.7 may make things interesting
Last edited by BayeauxLex; Jul 14, 2024 at 08:29 PM.
I will run 93 in the truck to next track day and see how she pulls and mpg. I’m willing to try it. I remember exactly what I averaged and how far a tank took me.
I should’ve tried 93 just now as I stopped to refuel. I pulled 35 gallons into a 38 gallon tank. Right now all I’m thinking about is blower!!
The dreaded V35A does tow better!! Especially on hills. Blower on 5.7 may make things interesting
How much that cost you? That would cost $220CAN up here.
