High Test or Regular Gas? Regular XLR ....NOT the V.

[anthem]

What is the consensus? I have seen regular recommended as well as premium. Premium is about 65 cents a gallon more than Regular. I made the mistake of using Regular in my Corvette one time and that was a HUGE mistake. It ran like crap! My XLR is being delivered tomorrow.....can't wait!

 

[pure zen]

Read my post on this thread.....should answer your question:
.

Owner of a 2004 XLR...

Hey there, So I bought a 2004 XLR back in November. I was living in Montana so I didn't drive it much, it was stored. Now, I have moved to Texas and it is my daily driver. So, now that I am actually driving it, I have some questions... Oil filter, what do you recommend? The caps on my rims are...

www.xlr-net.com

 

[beaver_jd]

I use the premium with the highest octane I can get.
John F.

 

[richardyoo]

I have personally reviewed the timing tables in the my V with both EFIlive and HPtuners - and you can clearly see a "low octane" timing table...

That is to say that it will not damage anything if you use regular fuel... but you will lose power....

In a forced induction set up like the supercharger motor in the XLR-V it will make a significant difference in power output as the higher compression will cause detonation... I have also witnessed this when datalogging and you can see the timing being pulled due to knock when there's insufficient octane.

So while I generally agree with purezen's post about it, the power difference will be more apparent in the V. However, if you don't need or want the extra power, you can run regular fuel without any concern - the motor will protect itself from damage.

 

[Grocery-Gtr]

What is the consensus? I have seen regular recommended as well as premium. Premium is about 65 cents a gallon more than Regular. I made the mistake of using Regular in my Corvette one time and that was a HUGE mistake. It ran like crap! My XLR is being delivered tomorrow.....can't wait!

Taken from page 6-5 and 6-6 of the XLR manuel.

Gasoline Octane

Use premium unleaded gasoline with a posted octane of 91 or higher for best performance. You may also use middle grade or regular unleaded gasoline rated at 87 octane or higher, but your vehicle’s acceleration may be slightly reduced. If the octane is less than 87, you may get a heavy knocking noise when you drive. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. Otherwise, you might damage your engine."

Additives

To provide cleaner air, all gasolines in the United States are now required to contain additives that will help prevent engine and fuel system deposits from forming, allowing your emission control system to work properly. In most cases, you should not have to add anything to your fuel. However, some gasolines contain only the minimum amount of additive required to meet U.S. Environmental Protection Agency regulations. General Motors recommends that you buy gasolines that are advertised to help keep fuel injectors and intake valves clean. If your vehicle experiences problems due to dirty injectors or valves, try a different brand of gasoline. Also, your GM dealer has additives that will help correct and prevent most deposit-related problems. Gasolines containing oxygenates, such as ethers and ethanol, and reformulated gasolines may be available in your area to contribute to clean air. General Motors recommends that you use these gasolines, particularly if they comply with the specifications described earlier.

Notice: Your vehicle was not designed for fuel that contains methanol. Do not use fuel containing methanol. It can corrode metal parts in your fuel system and also damage the plastic and rubber parts. That damage would not be covered under your warranty.

Some gasolines that are not reformulated for low emissions may contain an octane-enhancing additive called methylcyclopentadienyl manganese tricarbonyl (MMT); ask the attendant where you buy gasoline whether the fuel contains MMT. General Motors does not recommend the use of such gasolines. Fuels containing MMT can reduce the life of spark plugs and the performance of the emission control system may be affected. The malfunction indicator lamp may turn on. If this occurs, return to your authorized GM dealer for service.

I use the highest octane available and then I use Chevron cause it has Techron additive already in it.....