Will 5w/1040 affect my mileage for summer months?

[ziggy]

Hello all car in question. is a 1998 toyota corolla. I like to use 5w30 synthetic winter, 10w30 dino spring, 10w30 synthetic summer, 5w30 dino fall.
I am using NAPA 10w30 now. just did an oil change, along with a NAPA silver filter. I have read many like to use at least 5w 40 in summer/ here where i am southwest CT, summer july -september, its unberable almost. humidity in the air, the nights are unberable to sleep unless you have A?C. 10 30 dino at least, ive noticed causes a tad more fuel consumption. temps usualy run those months, 97-102 degrees F..with hunidity. would a 5w 40 or 10 40 cause even more consuption over a dino 10 30? or what if it was synthetic?
I was at my local autozone yesterday..and looked at 5w and 10 40 oils. mobile n castrol synthetic had 0w40...also 5w 40 and 1040.. synthetics mostly (5w40)..the rest all had 10 40.
Ive been told, with 10 30, fuel loss is at about 2%...so i can only imagine with 5w40 or 1040..unless the 5w40 is thinner if synthetic? had thought about running high mileage 5w30 or 10 30//but wanna try a 5w40 if it dosnt affect my mileage that bad...

 

[Garak]

You will lose mileage, of course. However, it will be within statistical noise and you will not be able to measure it. You very easily could run a 5w-30 all year (conventional or otherwise) or a 5w-40 all year.

 

[AKhan87]

Woah woah you said a lot there, half of that didn't make much sense.
I doubt it is measurable mpg loss on different weights

Oil consumption is generally less on heavier oils.

You have a 1ZZ-FE Which has a design flaw, I doubt any oil with lessen the affect for you as I tried 5w30 to 15w50 in my 1ZZ-FED, Dino and Synthetics, didn't matter what went in, oil loss was the same for me.

Do the rebuild it's a fairly doable DIY, especially if you have a weekend off and are not completely useless with tools.

For most people that are the original owners or owned the vehicle before oil burning started and topped it regularly, the rebuild is worth as the engine itself is very durable.

 

[Merkava_4]

Originally Posted By: ziggy
Hello all car in question. is a 1998 toyota corolla. I like to use 5w30 synthetic winter, 10w30 dino spring, 10w30 synthetic summer, 5w30 dino fall.


That tells me right there you're changing the oil every 3 months.

Lots of people will read that without thinking, but a wise old man catches everything.

 

[eljefino]

Originally Posted By: Garak
You will lose mileage, of course. However, it will be within statistical noise and you will not be able to measure it. You very easily could run a 5w-30 all year (conventional or otherwise) or a 5w-40 all year.


^ what he said.

Remember your car's thermostat temp is 190 so when ambient goes from 60 to 90 that only means you lose 30% of radiator-to-air cooling capacity. Stick a scangauge on and see if you're still running thermostat temp. As long as all your air dams are still in place I bet you would be.

However the flipside is your car is known for burning oil and I'd at least put "premium" oil in it. Maybe 15w40 every summer to clean things out and syn the rest of the time.

 

[ziggy]

wow@15w40? ide be filling the tank like every 4 days! lol. lots of stop n go traffic here. i average at near emtpy tank, 7 1/2 gallons too fill. with 5w30 that will last me 2 weeks. on 10w30 it will last week and a half..so ide imagine 1040 o 15w40 would be like 4 days..or so it would seem to me.
why would 1540 clean it out? it cleans better than a 5w30 or 10w30?

 

[Trav]

Try a piston soak first and see if that helps.
Some older Toyota engines actually do better with xw-20 and some better with xw-40, try both.
If you try xw-20 don't be surprised to see consumption increase for the first few OCI. Mobil 1 AFE 0w-20 is a good choice, it is a good cleaner. You might be surprised.

 

[fdcg27]

You won't notice any loss in fuel economy since it'll be too small to measure.
I agree with Garak in that a 5W-30 would be suitable for year 'round use in this engine.
There is no need to bump up a grade for the warmer months, although it wouldn't do any harm either.
The best reason to use a 10W-30 (some of which are actually thinner at operating temperatures than some 5W-30s) or a 10W-40 would be if you got it dirt cheap.
Either would be okay for the warmer months, but neither grade would be my first choice for your engine.

 

[bullwinkle]

A little confused here-why not run a 5W30 HM oil, either a full synthetic (like Mobil 1 HM or syn MaxLife), or even a syn blend (like regular 5W30 ML or Defy) year round? You'll get the high temperature protection you need, combined with good cold pumpability. For instance, my (way overloaded) work van gets MaxLife 5W20 year-round every 5 K-and it gets worked HARD, esp. in summer-doesn't use a drop of oil!

 

[tig1]

Using a 40 vs 30wt might increase your oil temp slightly. No advantage to a 40. Use 5-30 years round.

 

[bigt61]

5W-30 MaxLife year round - simple and cheap. Change it every 5000 miles and keep it topped off.

 

[aquariuscsm]

I agree with the HM oil recommendation. Try a good 10W30 HM oil (Maxlife,GTXHM,etc) and see how it goes.

 

[Roob]

As others have said, a heavier oil will cause mileage loss.
You could always go another way and try a conventional/synthetic in 5w20 as your car is also specced for that weight.
5w20 or 5w30 will have no issues whatsoever year round in the car, no need to go to a heavier grade.

 

[gathermewool]

I live an hour from you. Last year was exceptionally hot, and I only remember a few days at the temperatures you mention, a couple of weeks worth of uncomfortably hot days, and 6 weeks of very warm weather.

Regardless, someone mentioned the car self-regulating and I mostly agree. For a vehicle that doesn't have an oil cooler I wouldn't be surprised to see higher bulk temperatures, which is why running a 10W-30 might not be a bad idea, IMO.

Originally Posted By: Merkava_4
Originally Posted By: ziggy
Hello all car in question. is a 1998 toyota corolla. I like to use 5w30 synthetic winter, 10w30 dino spring, 10w30 synthetic summer, 5w30 dino fall.


That tells me right there you're changing the oil every 3 months.

Lots of people will read that without thinking, but a wise old man catches everything.

I'm glad I'm not the only one who caught that.

OP, unless you're driving under monstrous conditions, it seems to be that you could pick one good oil and weight and run it AT LEAST 6 months, changing it in the Spring and Fall if you really want to run two different weights.

If you have excessive consumption, then experimenting with an XW-40 might be prudent. I wouldn't run a heavier oil expecting it to protect better, however. IMO, based on what I've read, a heavier oil will usually raise oil temperatures, may raise pressure much higher than required to lubricate, and could has the potential to either raise or lower the amount of consumption you experience -- contrary to what a previous poster mentioned, I've seen consumption change both ways when going heavier then lighter and back again.