87 vs 93 for 2014 is250
06-02-14, 12:43 AM
#18
Pole Position
Join Date: Dec 2007
Location: california
Posts: 309
Likes: 0
Received 0 Likes
on
0 Posts
Switching from premium to 87 with our car is like going from 56k to 14.4k internet. Gas mileage will suck too so if you enjoy driving like a grandma and wasting money, go for it. I know because my dad filled up with 87 before and never again.
06-02-14, 01:29 AM
#19
The sales lady told me the 3IS can take 87 octane now so of course I had to test this myself ...on their loaner car I had for a month.
Sure enough, fuel efficiency went down and it felt sluggish. Most people buy their gas based on how much they see on the sign. They will drive across town for a 10cent saving per gallon. I buy the gas based on how many miles I get per tank. If I get 25 more miles per tank using a different station (I've gotten more depending on the station) than that obliterates a 10cent savings. Only way a 10cent savings would mean more at that point would be if the gas was cheaper than $1.30. So even with a 20cent difference, gas would have to be cheaper than $2.60/tank. So not only do you gain a sluggish car for your 87 octane but you also pay more in the long run. The only thing 87 octane buys you is a receipt with a lower number.
Sure enough, fuel efficiency went down and it felt sluggish. Most people buy their gas based on how much they see on the sign. They will drive across town for a 10cent saving per gallon. I buy the gas based on how many miles I get per tank. If I get 25 more miles per tank using a different station (I've gotten more depending on the station) than that obliterates a 10cent savings. Only way a 10cent savings would mean more at that point would be if the gas was cheaper than $1.30. So even with a 20cent difference, gas would have to be cheaper than $2.60/tank. So not only do you gain a sluggish car for your 87 octane but you also pay more in the long run. The only thing 87 octane buys you is a receipt with a lower number.
06-02-14, 05:29 AM
#20
Rookie
Join Date: Apr 2014
Location: Florida
Posts: 61
Likes: 0
Received 0 Likes
on
0 Posts
06-02-14, 05:33 AM
#21
Rookie
Join Date: Apr 2014
Location: Florida
Posts: 61
Likes: 0
Received 0 Likes
on
0 Posts
It didn't say the 2.5L had 300hp at the crank, just more like 220hp at the crank. It is making more than rated by Lexus. Exactly how much is hard to tell without placing an engine on a independent engine Dyno (not a chassis Dyno).
The chassis Dyno numbers for both the 2.5L and 3.5L don't add up with my extensive experience.
The chassis Dyno numbers for both the 2.5L and 3.5L don't add up with my extensive experience.
06-02-14, 05:49 AM
#22
Yes, lexus has been underrating their cars just to make sure they make themselves not look too competitive in this really non competitive and relaxed segment of cars (the entry level lux sport sedan).
There are plenty of 265-275whp dynos out there for stock IS350s which is about spot on what you would expect.
If you go on any car forum for any make and model of car you will inevitiably find people who all think their cars are underrated from the factory.
The quarter mile times and trap speeds dont lie. There's not a lot more going on in these engines than what they are rated for.
Mike
06-02-14, 05:53 AM
#23
Rookie
Join Date: Apr 2014
Location: Florida
Posts: 61
Likes: 0
Received 0 Likes
on
0 Posts
Cars nowadays have equipped with octane sensors.
In another word, your car will adopt your cheapass behaviour.
However, it won't have the full 200hp you are already looking down at and it will have worse fuel consumption. You will end up using more fuel than you should so you are not saving up any better and you are loosing power.
Do your car a favor, just put in the recommended octane.
In another word, your car will adopt your cheapass behaviour.
However, it won't have the full 200hp you are already looking down at and it will have worse fuel consumption. You will end up using more fuel than you should so you are not saving up any better and you are loosing power.
Do your car a favor, just put in the recommended octane.
All modern engines have what's called a "knock sensor". This allows the ECU to listen for knock due to pre-ignition or detonation and retards ignition timing to help combat the knock it hears. The problem with this - it is reactive rather than proactive. It reacts after the knock event, which can only prevent damage so much.
That being said, engine manufacturers know that people are generally stupid to engine mechanics and the science behind it, so they factor-in a certain safety margin in the tune and in the engineering of the engine itself.
06-02-14, 06:04 AM
#25
Rookie
Join Date: Apr 2014
Location: Florida
Posts: 61
Likes: 0
Received 0 Likes
on
0 Posts
LOL.
Yes, lexus has been underrating their cars just to make sure they make themselves not look too competitive in this really non competitive and relaxed segment of cars (the entry level lux sport sedan).
There are plenty of 265-275whp dynos out there for stock IS350s which is about spot on what you would expect.
If you go on any car forum for any make and model of car you will inevitiably find people who all think their cars are underrated from the factory.
The quarter mile times and trap speeds dont lie. There's not a lot more going on in these engines than what they are rated for.
Mike
Yes, lexus has been underrating their cars just to make sure they make themselves not look too competitive in this really non competitive and relaxed segment of cars (the entry level lux sport sedan).
There are plenty of 265-275whp dynos out there for stock IS350s which is about spot on what you would expect.
If you go on any car forum for any make and model of car you will inevitiably find people who all think their cars are underrated from the factory.
The quarter mile times and trap speeds dont lie. There's not a lot more going on in these engines than what they are rated for.
Mike
Btw, manufacturers are known to under-rate their engines all the time. They have multiple reasons for this.
Also, there will always be some engines that perform better than others (no 2 engines perform alike). You can't look at the low numbers without factoring-in the high numbers. Plus, every Dyno is different. I've done the proper research to back-up my claim, you can rest-assure.
Beyond that, think what you want to think. I couldn't care less, to be honest.
P.s. There is more to 1/4 mile times and trap speeds than engine HP, but I digress.
Last edited by CTLG; 06-02-14 at 06:10 AM.
06-02-14, 06:39 AM
#26
The pursuit of F
From my personal experience (and I've posted this several times elsewhere), 87 octane makes the car feel more sluggish while 94 (best we can get here) livens up the response.
06-02-14, 06:45 AM
#27
I'm not just "some guy on a enthusiast forum". I have years and years of professional tuning experience.
Btw, manufacturers are known to under-rate their engines all the time. They have multiple reasons for this.
Also, there will always be some engines that perform better than others (no 2 engines perform alike). You can't look at the low numbers without factoring-in the high numbers. Plus, every Dyno is different. I've done the proper research to back-up my claim, you can rest-assure.
Beyond that, think what you want to think. I couldn't care less, to be honest.
P.s. There is more to 1/4 mile times and trap speeds than engine HP, but I digress.
Btw, manufacturers are known to under-rate their engines all the time. They have multiple reasons for this.
Also, there will always be some engines that perform better than others (no 2 engines perform alike). You can't look at the low numbers without factoring-in the high numbers. Plus, every Dyno is different. I've done the proper research to back-up my claim, you can rest-assure.
Beyond that, think what you want to think. I couldn't care less, to be honest.
P.s. There is more to 1/4 mile times and trap speeds than engine HP, but I digress.
12% is not "extremely low" in todays modern vehicles at all. Think torque converter lock up and think new 8 speed tranny. Back when 15% was sometimes considered the standard they had not dreamed of todays sophisticated 8 speed trannys, new damper technology increasing road contact, advances in tire tread technology, and advances in NVH that can lead to dyno losses.
you are discounting the low and average dyno numbers because I see a whole lot in the 260s and 270s for stock, a few in the 250s, and a few in the 280s. Show me a MAHA plot. Or please show me more than 10 dynos in the 300whp range (what you would need to see in order to start even considering 340chp claims). I havent even seen one in the 300whp range stock.
Anywho, not really that important to disagree about. Hey, maybe they are really 500chp from the factory. It's just a shame I cant keep up with a 300hp S4, or a 300hp 335i, or a 328hp Q50, or a ...
Mike
Last edited by bhvrdr; 06-02-14 at 07:09 AM.
06-02-14, 01:11 PM
#28
Rookie
Join Date: Apr 2014
Location: Florida
Posts: 61
Likes: 0
Received 0 Likes
on
0 Posts
Well i'm glad you have "years and years" of tuning experience and not just years of tuning experience.
12% is not "extremely low" in todays modern vehicles at all. Think torque converter lock up and think new 8 speed tranny. Back when 15% was sometimes considered the standard they had not dreamed of todays sophisticated 8 speed trannys, new damper technology increasing road contact, advances in tire tread technology, and advances in NVH that can lead to dyno losses.
you are discounting the low and average dyno numbers because I see a whole lot in the 260s and 270s for stock, a few in the 250s, and a few in the 280s. Show me a MAHA plot. Or please show me more than 10 dynos in the 300whp range (what you would need to see in order to start even considering 340chp claims). I havent even seen one in the 300whp range stock.
Anywho, not really that important to disagree about. Hey, maybe they are really 500chp from the factory. It's just a shame I cant keep up with a 300hp S4, or a 300hp 335i, or a 328hp Q50, or a ...
Mike
12% is not "extremely low" in todays modern vehicles at all. Think torque converter lock up and think new 8 speed tranny. Back when 15% was sometimes considered the standard they had not dreamed of todays sophisticated 8 speed trannys, new damper technology increasing road contact, advances in tire tread technology, and advances in NVH that can lead to dyno losses.
you are discounting the low and average dyno numbers because I see a whole lot in the 260s and 270s for stock, a few in the 250s, and a few in the 280s. Show me a MAHA plot. Or please show me more than 10 dynos in the 300whp range (what you would need to see in order to start even considering 340chp claims). I havent even seen one in the 300whp range stock.
Anywho, not really that important to disagree about. Hey, maybe they are really 500chp from the factory. It's just a shame I cant keep up with a 300hp S4, or a 300hp 335i, or a 328hp Q50, or a ...
Mike
06-02-14, 09:52 PM
#29
Well i'm glad you have "years and years" of tuning experience and not just years of tuning experience.
12% is not "extremely low" in todays modern vehicles at all. Think torque converter lock up and think new 8 speed tranny. Back when 15% was sometimes considered the standard they had not dreamed of todays sophisticated 8 speed trannys, new damper technology increasing road contact, advances in tire tread technology, and advances in NVH that can lead to dyno losses.
you are discounting the low and average dyno numbers because I see a whole lot in the 260s and 270s for stock, a few in the 250s, and a few in the 280s. Show me a MAHA plot. Or please show me more than 10 dynos in the 300whp range (what you would need to see in order to start even considering 340chp claims). I havent even seen one in the 300whp range stock.
Anywho, not really that important to disagree about. Hey, maybe they are really 500chp from the factory. It's just a shame I cant keep up with a 300hp S4, or a 300hp 335i, or a 328hp Q50, or a ...
Mike
12% is not "extremely low" in todays modern vehicles at all. Think torque converter lock up and think new 8 speed tranny. Back when 15% was sometimes considered the standard they had not dreamed of todays sophisticated 8 speed trannys, new damper technology increasing road contact, advances in tire tread technology, and advances in NVH that can lead to dyno losses.
you are discounting the low and average dyno numbers because I see a whole lot in the 260s and 270s for stock, a few in the 250s, and a few in the 280s. Show me a MAHA plot. Or please show me more than 10 dynos in the 300whp range (what you would need to see in order to start even considering 340chp claims). I havent even seen one in the 300whp range stock.
Anywho, not really that important to disagree about. Hey, maybe they are really 500chp from the factory. It's just a shame I cant keep up with a 300hp S4, or a 300hp 335i, or a 328hp Q50, or a ...
Mike
But those cars do make way more power than factory claimed hp.
Last edited by forum429; 06-02-14 at 10:26 PM.
