Fuel discussions/questions - Octane Regular or Premium (merged threads)
04-26-18, 07:48 AM
#241
This thread has a lot of info
https://www.clublexus.com/forums/gx-...7-89-91-a.html
From what i understand other lexus models using the same engine call for regular. I dont know if something changed for GX specifically it requires premium. I always use top tier premium fuel regardless. Ive always heards its a wash, that the mpg loss with regular equaled or cost more than just using premium and getting that extra mpg or 2.
https://www.clublexus.com/forums/gx-...7-89-91-a.html
From what i understand other lexus models using the same engine call for regular. I dont know if something changed for GX specifically it requires premium. I always use top tier premium fuel regardless. Ive always heards its a wash, that the mpg loss with regular equaled or cost more than just using premium and getting that extra mpg or 2.
04-26-18, 01:11 PM
#242
i live at altitude, so i use 87 (we have 85 ,87 and 91)
i was told by the dealer i can use 85 with no issues here. i found that running 85 car was more sluggish. 87 it runs pretty smooth and avg 16-17mpg
i dont think i will get a huge increase of MPGs on 91 to make up for the 30c/gallon difference. if i make it down to sea level i will put more premium fuel in
i was told by the dealer i can use 85 with no issues here. i found that running 85 car was more sluggish. 87 it runs pretty smooth and avg 16-17mpg
i dont think i will get a huge increase of MPGs on 91 to make up for the 30c/gallon difference. if i make it down to sea level i will put more premium fuel in
04-26-18, 08:53 PM
#243
Hello Leftyguns, I am here in Lakewood, Colorado (~6,000 ft. elevation where we live) and just acquired a nice used 2012 GX460. I have been running it on 87 octane Mobil gas and it seems ok. We are averaging about 15mpg if we are really easy on it. There is a Conoco station nearby that usually has 85 regular, 87 octane that only has 6% ethanol, and 91 octane with no ethanol, but something was wrong with his 87 octane tank the last two times I wanted to try his gas.
I have been using the 87 octane with 6% ethanol from this station for 2 years in my 2006 Land Cruiser and it consistently gets 1.5 mpg better mileage than the 87 octane from other stations. When I run his non-ethanol 91 octane for about 2 tanks (probably long enough for the computer to re-tune to the higher octane fuel), I get another .5 mpg increase over the good 87 octane.
From my viewpoint, the GX460 engine(1UR-FE) doesn't have the low-end torque that the 2006 Land Cruiser 4.7 (2UZ-FE VVTI) has. I am wondering if the GX460 will be as responsive to the octane boost and better fuel quality as my Land Cruiser has been. The GX460 has a sweet-sounding engine, but I can tell it really only starts running strong at 3500+ when it hits the beefier part of the torque curve.
I am curious to see how much this has to do with octane and fuel-quality, or the programming for the electronic throttle control algorithm (how fast the throttle plate is really opened when you mash the accelerator pedal), the mechanical camshaft specs, the VVTI controller programming, etc., as well as the airflow dynamics of the intake ports of the cylinder heads (how well the heads flow at low to mid-lift numbers).
I have been using the 87 octane with 6% ethanol from this station for 2 years in my 2006 Land Cruiser and it consistently gets 1.5 mpg better mileage than the 87 octane from other stations. When I run his non-ethanol 91 octane for about 2 tanks (probably long enough for the computer to re-tune to the higher octane fuel), I get another .5 mpg increase over the good 87 octane.
From my viewpoint, the GX460 engine(1UR-FE) doesn't have the low-end torque that the 2006 Land Cruiser 4.7 (2UZ-FE VVTI) has. I am wondering if the GX460 will be as responsive to the octane boost and better fuel quality as my Land Cruiser has been. The GX460 has a sweet-sounding engine, but I can tell it really only starts running strong at 3500+ when it hits the beefier part of the torque curve.
I am curious to see how much this has to do with octane and fuel-quality, or the programming for the electronic throttle control algorithm (how fast the throttle plate is really opened when you mash the accelerator pedal), the mechanical camshaft specs, the VVTI controller programming, etc., as well as the airflow dynamics of the intake ports of the cylinder heads (how well the heads flow at low to mid-lift numbers).
Last edited by Gxxr; 04-26-18 at 09:07 PM.
04-27-18, 12:15 AM
#244
Originally Posted by VentoGT
If you can afford a $55K+ truck with an engine designed for premium fuel, I'd fill it with high test...not worth the hassle of possibly damaging something not to mention that if something goes wrong and it's obvious regular fuel was used when premium was specified on the fuel door and in the manual, you could open up a can of worms of 'whose fault was it' for warranty work. I may be paranoid but warranty is a big plus in buying a new car, and following recommended procedures from the company that designed the car is generally a good idea.
04-27-18, 10:21 PM
#246
If I was at sea-level or less than 2,000 ft. elevation, I would probably be running premium as well, but at an altitude like Denver has (5,280+), the effective compression of the engine is much lower than at sea-level, thus reducing the effective requirement for high octane fuel. For every 1,000 ft you ascend in elevation, you loose ~ 3.5% in horsepower/torque; at 6,000 ft where I live, you can tell that it really knocks the power down on an engine, to the magnitude of a 21% decrease. So, our GX460 with 301hp at sea-level only has 238hp at 6,000 ft. elevation where I live.
When I lived in Texas, I always ran premium in my Land Cruisers and in my turbo Subarus.
When I lived in Texas, I always ran premium in my Land Cruisers and in my turbo Subarus.
05-03-18, 01:55 AM
#247
The premium recommendation from Lexus has little to do power or fuel economy. Lexus touts itself as one of the most reliable brands in the world, if not the most and it even touts Lexus > Toyota in reliability.
1. An engine running premium fuel will be a bit more efficient, reducing the amount of NVH levels in the cab. Lexus really goes out of the way to make things quiet and comfortable, this is one part of the equation. They rethink everything in the design process, they're a smart company.
2. Premium fuel has much much better additives and detergents than Regular or Mid-grade fuels. This is huge because an engine run on premium won't run as rough as an engine feed regular at 100,000 and then 200,000. Too many of these GX/LX's running to 300K. That is part of why they hold value so well. Less deposits in these engines, etc really add up in the long haul.
My civic for example, runs much much smoother on Premium vs. Regular, especially at idle at a red light, but it's just not really worth the price increase in my opinion. But if you're already spending big money on a gas guzzler, does that difference matter to you?
I would suggest to those in areas where E85/Flex Fuel/E30/E20/E15 can be found, the GX/LX can easily be converted to run those fuels mentioned, like 1-2-3 easy. They are not only much cheaper than Premium, they will keep your engine clean, reduce wear and increase performance and efficiency, especially in the long run. I'll be shooting for a 25K oil change on my GX soon and E85 will definately be part of the reason as to why it can.
At the time of this post, E85 - $1.88 Premium - $4.15.
edit: E85 Tank - $43.24 Premium 93 Tank $95.45 Difference = $52.51 per tank or $3,500 per year for the average driver filling up once per week.
1. An engine running premium fuel will be a bit more efficient, reducing the amount of NVH levels in the cab. Lexus really goes out of the way to make things quiet and comfortable, this is one part of the equation. They rethink everything in the design process, they're a smart company.
2. Premium fuel has much much better additives and detergents than Regular or Mid-grade fuels. This is huge because an engine run on premium won't run as rough as an engine feed regular at 100,000 and then 200,000. Too many of these GX/LX's running to 300K. That is part of why they hold value so well. Less deposits in these engines, etc really add up in the long haul.
My civic for example, runs much much smoother on Premium vs. Regular, especially at idle at a red light, but it's just not really worth the price increase in my opinion. But if you're already spending big money on a gas guzzler, does that difference matter to you?
I would suggest to those in areas where E85/Flex Fuel/E30/E20/E15 can be found, the GX/LX can easily be converted to run those fuels mentioned, like 1-2-3 easy. They are not only much cheaper than Premium, they will keep your engine clean, reduce wear and increase performance and efficiency, especially in the long run. I'll be shooting for a 25K oil change on my GX soon and E85 will definately be part of the reason as to why it can.
At the time of this post, E85 - $1.88 Premium - $4.15.
edit: E85 Tank - $43.24 Premium 93 Tank $95.45 Difference = $52.51 per tank or $3,500 per year for the average driver filling up once per week.
Last edited by danielTRLK; 05-03-18 at 02:06 AM.
05-03-18, 08:01 AM
#248
How does your MPG compare between e85 and premium 93?
I'd be sticking to top tier fuels too. Using shell, exxon, sunoco etc over off brands is going to make a long term difference in engine wear and buildup. Maybe not so much as the LS/GS's DI engine would but still.
I'd be sticking to top tier fuels too. Using shell, exxon, sunoco etc over off brands is going to make a long term difference in engine wear and buildup. Maybe not so much as the LS/GS's DI engine would but still.
05-03-18, 09:39 AM
#249
Shell V-Power 93 is currently best fuel on main stream market.
About 8-10% loss in fuel economy. But you can definitely feel the difference at idle and even just running in general.
Also, E85 is much cleaner and doesn’t support foreign involvement or foreign interests.
I don't mind excessive idling with my engine when I run E85 because it is tremendously easier on the engine. Idling with gas is super hard on engines.
About 8-10% loss in fuel economy. But you can definitely feel the difference at idle and even just running in general.
Also, E85 is much cleaner and doesn’t support foreign involvement or foreign interests.
I don't mind excessive idling with my engine when I run E85 because it is tremendously easier on the engine. Idling with gas is super hard on engines.
05-03-18, 10:01 AM
#250
I ran quite a few tankfuls of regular through ours. There was no difference in noise levels, no difference in fuel economy, and any difference in performance was virtually impossible to discern. It may be a little more responsive to throttle input which would be expected if engine timing is effected. But even that is hard to tell.
I did go back to premium simply because I can afford it and we only put gas in it every two weeks, and sometimes even three weeks. I still believe that based upon my experience and the information in the other thread about the same engine in the Toyota truck being rated for regular, that premium should not be required. But that thread got a little contentious so I’m not going to argue the point again.
I did go back to premium simply because I can afford it and we only put gas in it every two weeks, and sometimes even three weeks. I still believe that based upon my experience and the information in the other thread about the same engine in the Toyota truck being rated for regular, that premium should not be required. But that thread got a little contentious so I’m not going to argue the point again.
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Rygar470 (07-01-20)
05-03-18, 10:44 AM
#251
Your point is valid but just to note some things.
Automotive engineers do not test things with how they felt. They send the cars to labs, that fire back results.
If the lab says that a rubber bushing reduced 1% NVH levels over X model, they will make a swap. I have a very good friend at SKF who spends all day listening to bearings for luxury brands trying to reduce 0.01% in noise levels emitted. So while not something you can particularly say you will feel, combined and added with thousands of other reductions, it becomes significant. Just like racing. One panel won’t make or break a race but a dozen panels, A/C, etc can.
Maybe I should elaborate better. Regular gas over a long period of time will leave the engine with more deposits and wear, than premium will. So over thousands of miles the effects will begin to set in. It will run poorly towards the end vs. Running a lot cleaner.
Automotive engineers do not test things with how they felt. They send the cars to labs, that fire back results.
If the lab says that a rubber bushing reduced 1% NVH levels over X model, they will make a swap. I have a very good friend at SKF who spends all day listening to bearings for luxury brands trying to reduce 0.01% in noise levels emitted. So while not something you can particularly say you will feel, combined and added with thousands of other reductions, it becomes significant. Just like racing. One panel won’t make or break a race but a dozen panels, A/C, etc can.
Maybe I should elaborate better. Regular gas over a long period of time will leave the engine with more deposits and wear, than premium will. So over thousands of miles the effects will begin to set in. It will run poorly towards the end vs. Running a lot cleaner.
Last edited by danielTRLK; 05-03-18 at 10:51 AM.
05-03-18, 11:23 AM
#252
Top Tier gas brands have more/better detergents (than un-name lower-tier brands) which leaves less deposits or they clean out more deposits - NOT regular vs. Premium as you stated. Premium gas contains HIGHER octane level comparing to regular gas.
Not to worry too much about Reg or Prem in the GX. Just pick you poison.
Note:
2012 or older RX350 requires Premium while 2013-2015 RX350 with EXACTLY the same engine/TX asks for Regular. Similar case is for ES350. The changes are due to high gas prices (esp. Prem) in 2012.
Other Toyota and Lexus that are loosely related:
4.6L V8 in Tundra asks for Regular, similar engine in GX460 asks for Premium
4.7L V8 in Tundra and 4Runner ask for Regular, similar engine in GX470 asks for Premium
5.7L V8 in LC and Tundra ask for Regular, similar engine in LX570 asks for Premium
05-03-18, 12:35 PM
#253
Not trying to be a jerk but that isn’t quite right.
Top tier just means that the brand has meet X amount of detergency levels in their fuel.
Premium fuels in in all the testing I’ve ever done carry much much better additive packs than Regular grade. Top tier is a crappy standard that is exceeded by almost all premium fuels but barely achieved by the Regular grades.
Mobil, BP, Chevron, Shell and the other big players place more robust and solvent detergents and additives in the premium fuels. It’s why engines run on premium fuels even those whom don’t require such, are cleaner and more efficient.
This is really why Lexus and the other luxury brands want the premium fuels like Nitro V-Power run in these cars. Not like most people won’t have the cash to run better fuels.
Top tier just means that the brand has meet X amount of detergency levels in their fuel.
Premium fuels in in all the testing I’ve ever done carry much much better additive packs than Regular grade. Top tier is a crappy standard that is exceeded by almost all premium fuels but barely achieved by the Regular grades.
Mobil, BP, Chevron, Shell and the other big players place more robust and solvent detergents and additives in the premium fuels. It’s why engines run on premium fuels even those whom don’t require such, are cleaner and more efficient.
This is really why Lexus and the other luxury brands want the premium fuels like Nitro V-Power run in these cars. Not like most people won’t have the cash to run better fuels.
05-03-18, 02:18 PM
#254
Advanced
I know this topic has been through discussions really often and most common and usual debates. However, I'm still curious to know if someone is driving his/ her GX460 on regular without any issues.
I'm taking the delivery of my 2018 GX next week for which I'm really excited. I met a gentleman who's a huge fan of this truck and currently driving his 4th GX and as per him he has never used Premium with no issues even after 200K miles on one of his previous ones.
Has anyone else tried this with a success? Will appreciate some feedback please.
TIA
I'm taking the delivery of my 2018 GX next week for which I'm really excited. I met a gentleman who's a huge fan of this truck and currently driving his 4th GX and as per him he has never used Premium with no issues even after 200K miles on one of his previous ones.
Has anyone else tried this with a success? Will appreciate some feedback please.
TIA
Briefly, if you look at the engine specs, there's no apparent reason from an engineering standpoint why the 1UR-FE in the GX requires premium while the 1UR-FE in every Toyota model requires regular. Identical compression specs, identical dimensions, same part numbers and everything. In fact, the Tundra is rated for more power on regular than the GX is rated for on premium.
If you read enough, there's a marketing trend since the 90s among luxury marques to make premium fuel "required" or "recommended" in order to make the product appear more premium. As GoHuskers pointed out above, Lexus has changed the premium "requirement" to regular in their RX without changing the hardware. At the time it was a marketing decision as RX/ES buyers were more cost-conscious and fuel prices were high.
I generally fill up at Costco (which is top tier) but will fill up at an Exxon, Shell, Chevron from time to time. Always 87. Usually saves maybe $6.00 or $7.00 a tank at Costco, and anywhere from $15.00 to $20.00 at other stations vs filling with premium. I could easily afford to fill premium but I'd rather keep the money in my pocket.
On other models it could definitely be justified, particularly with high compression and/or turbocharged motors, but in this case I don't think it's an issue. If you run your GX especially hard it might be worth a premium fill (same thing for the Tundra) but I doubt that applies to most owners. And all of that said, if it makes someone feel good to put premium in his or her GX, that's perfectly fine with me.
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Rygar470 (07-01-20)
05-03-18, 02:28 PM
#255
On my last GX 470, I ran regular unleaded (87 octane) for several years and never had a single issue. Vehicle had about 150k miles on it and said "premium only".
I run 91 octane (highest I can get in my state) on this GX just because it's so new and still under warranty, just a little extra insurance in case I ever have an engine issue (which is probably silly)
Everything I've read is you can run regular unleaded with no issues and these same engines are made for a variety of markets where octane is all over the place.
It's also well established that you can eek out a little extra efficiency on higher octane, which is probably the main reason Lexus made their models specify super unleaded. It gives the vehicle a slightly higher mpgs and acceleration and most prospective buyers of luxury cars don't care about spending a few dollars extra at the pump.
The only time I would really be concerned about octane is on an older vehicle (like pre-1990s era) where cars timing was locked in or on something that was turbo-charged or supercharged.
I run 91 octane (highest I can get in my state) on this GX just because it's so new and still under warranty, just a little extra insurance in case I ever have an engine issue (which is probably silly)
Everything I've read is you can run regular unleaded with no issues and these same engines are made for a variety of markets where octane is all over the place.
It's also well established that you can eek out a little extra efficiency on higher octane, which is probably the main reason Lexus made their models specify super unleaded. It gives the vehicle a slightly higher mpgs and acceleration and most prospective buyers of luxury cars don't care about spending a few dollars extra at the pump.
The only time I would really be concerned about octane is on an older vehicle (like pre-1990s era) where cars timing was locked in or on something that was turbo-charged or supercharged.